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THE    WILEY    TECHNICAL   SERIES 

FOR 

VOCATIONAL    AND    INDUSTRIAL    SCHOOLS 

EDITED  BY 

JOSEPH    M.    JAMESON 

GIRARD  COLLEGE 


THE  WILEY  TECHNICAL  SERIES 

EDITED    BY 

JOSEPH  M.  JAMESON 


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A  corner  of  the  apartment  kitchen  of  the  Washington  Irving  High 

School 


FOOD 

ITS    COMPOSITION 
AND   PREPARATION 

A    TEXTBOOK  FOR   CLASSES 
IN  HOUSEHOLD  SCIENCE 


BY 

MARY  T.  DOWD 

AND 

JEAN  D.  JAMESON 

Teachers  of  Household  Science 
Washington  Irving  High  School,  New  York  City 


FIliST    EDITION 


'       '     >      J     J  *      >     0.        3i 


NEW  YORK 

JOHN  WILEY  &  SONS,  Inc. 

London:    CHAPMAN  &  HALL,    Limited 
1918 


COPTBIGHT,    1918 
BY 

MARY  T.  DOWD  and  JEAN  D.  JAMESON 


PRESS  OF 

BRAUNWORTH   &  CO. 

300K  MANUFACTURERS 

BROOKLYN,  N.  Y. 


^ 


PREFACE 


In  presenting  this  book  for  the  consideration  of  the 
pubHc,  the  authors  are  well  aware  of  the  present  very  general 
practice  of  furnishing  all  necessary  instructions  and  theory 
to  Domestic  Science  classes  through  the  medium  of  notes 
taken  by  the  students.  Indeed  it  is  to  the  conviction, 
resulting  from  long  experience  with  the  problem,  of  the 
futility  and  inefficiency  of  this  practice  that  the  book  owes 
its  origin.  Much  of  the  time  thus  spent  by  the  teacher  in 
dictating,  and  by  the  student  in  writing,  can  and  ought  to 
be  saved  for  more  profitable  use. 

It  is  questionable  whether  the  advantages  derived  from 
note  taking  by  elementary  classes  are  as  great  as  popularly 
supposed;  certainly  they  do  not  compensate  for  the  amount 
of  valuable  experience  in  the  broader  applications  of  the 
subject  that  is  lost  when  the  time  is  thus  used.  Moreover, 
notes  taken  hurriedly,  as  under  the  conditions  of  the  class 
room,  are  often  incorrectly  copied,  and  the  girl's  attention 
is  unfortunately  fixed  upon  the  mechanical  process  of  getting 
down  all  that  the  teacher  has  said,  rather  than  upon  the 
comprehension  of  what  has  been  said. 

It  is  believed  by  the  authors  that,  if  the  subject  is  to  be 
taught  with  any  degree  of  uniformity  throughout  a  large 
school  or  in  a  city  where  there  are  several  teachers  supposedly 
presenting  the  same  subject  matter,  there  should  be  some 
common  material  that  may  be  put  directly  in  the  hands  of 
the  pupils  for  home  study. 

The  text  is  an  elaboration  of  the  notes  dictated  by  the 
authors  to  their  own  High  School  classes.     It  is  designed 


IV  PREFACE 

to  supplement  the  laboratory  work  and  to  bring  to  the  pupils 
a  clearer  conception  of  the  relation  between  the  cost  of 
foods  and  their  nutritive  value. 

No  recipes  are  given  for  the  reason  that,  after  close 
association  with  many  Domestic  Science  teachers,  the  con- 
clusion has  been  reached  that  each  one  has  her  own  special 
recipes  and  considers  no  others  quite  so  good.  Again,  the 
tendency  of  the  age  is  to  get  away  from  the  teaching  of 
hard  and  fast  rules  for  doing  things  and  to  teach,  rather,  the 
application  of  well-defined  principles.  The  general  adoption 
of  a  card  catalogue  system  for  the  purpose  of  filing  recipes 
makes  a  cook  book  unnecessary. 

No  attempt  has  been  made  to  deal  with  such  matters  as 
setting  the  table,  table  service  or  table  etiquette,  as  it  is 
believed  that  these  can  be  taught  satisfactorily  only  by 
actual  demonstration  and  practice.  The  subject  of  special 
diets  for  invalids  and  infants  is  omitted  as  coming  more 
properly  within  the  scope  of  a  treatise  in  dietetics. 

In  studying  foodstuffs,  it  has  been  the  experience  of 
the  writers  that  a  consideration  of  the  simple  compound 
water,  made  up  of  but  two  elements,  is  the  natural  starting 
point  from  which  the  pupils  may  be  carried  by  easy  stages 
to  a  consideration  of  the  more  complex  compounds. 

A  vocabulary  of  the  subject  has  been  inserted  in  the 
course,  as  familiarity  with  the  commoner  technical  terms 
will  be  found  of  great  assistance  to  a  clear  understanding 
of  the  chapters  that  follow. 

Mary  T.   Dowd. 
Jean  D.  Jameson. 
New  York. 


CONTENTS 


CHAPTER  I 

PAGE 

Introductory 1 

Definition  of  Food. — Classification  of  Foods. — Food  as  a 
Source  of  Energy. — How  Food  is  Like  the  Body  Tissue. — 
Composition  of  Foodstuffs. — Tests  for  Foodstuffs. — Function 
of  Foodstuffs  in  the  Body. — Purposes  of  Cooking. — Processes 
of  Cooking . — Digestion . — Absorption . — Assimilation , 

CHAPTER  II 

Water 8 

Composition. — Kinds  of  Water. — Function  of  Water  in 
the  Body. — Water  in  Food. — Water  as  a  Cooking  Medium. 

CHAPTER  III 

Carbohydrate  in  the  Form  of  Sugar 12 

Composition.  —  Monosaccharides.  • —  Disaccharides.  ^Func- 
tion of  Sugar  in  Nutrition. — Digestion  of  Sugar. — Commercial 
Sugar. — Molasses. — Maple  Sugar. — Honey. — Effects  of  Cook- 
ing Sugar. 

'      CHAPTER  IV 

Carbohydrate  in  the  Form  of  Starch 18 

Composition. — Source  and  Structure. — Food  Value. — Func- 
tion in  the  Body. — Tests  for  Starch. — Cooking  of  Starch. — 
Cellulose.— Digestion  and  Food  Value  of  Cellulose. — Dextrin. 
— Glycogen. — Some  Unusual  Forms  of  Starch. — Tapioca,  Sago, 
and  Arrowroot. 

CHAPTER  V 

Cereal  Foods 24 

Cereals  as  Breakfast  Foods. — Wheat. — Oats. — Indian  Corn. 
— Rice. — Buckwheat. — Barley. — Rye. — Digestibility  of  Cere- 


vi  CONTENTS 

PAGE 

als. — Cooking  of  Cereals. — Macaroni,  Spaghetti,  and  Noodles. 
— Use  of  Double  Boiler. — The  Fireless  Cooker. — The  Thermos 
Bottle. — The  Pressure  Cooker. 


CHAPTER  VI 

Flour  Mixtures 39 

Definition. — Leavening  Agents. — Baking  Powders. — Clas- 
sification of  Flour  Mixtures. — Hot  or  Quick  Breads. — Cakes. — 
Sponge  Cakes. — Butter  Cakes. 

CHAPTER  VII 

Flour  Mixtures — Bread  and  Pastry 53 

Varieties  of  Wheat. — The  Protein  of  Wheat. — Milling  of 
Flour. — Yeast  Bread. — Bread  Mixer. — Kinds  of  Yeast. — 
Function  of  Yeast  in  Bread  Making. — Digestibility  of  Bread. — 
How  to  Know  Good  Bread. — Pastry. — Digestibility  of  Pastry. 

CHAPTER  VIII 

Vegetables 64 

Definition. — Classification  of  Vegetables. — Composition  and 
Food  Value  of  Vegetables. — Digestion  of  Vegetables. — Selec- 
tion and  Care. — Cooking  of  Vegetables. — Preserving  Vege- 
tables.— Legumes. — Food  Value. — Cooking. — Soy  Bean. — 
Tubers. — The  Dasheen. — Bulbs,  Leaves,  Stems,  and  Shoots. — 
Fruits. — Flower  Buds. — Digestion  and  Food  Value  of  Green 
Vegetables. 

CHAPTER  IX 

Fruits 77 

Definition.  —  Composition.  —  Digestibility.  —  Selection  of 
Fruit. — Preparation  and  Cooking. — Dried  Fruits. — Nuts. — 
Food  Value  of  Nuts. — Use  of  Nuts  in  Cooking. 

CHAPTER  X 

Fats  and  Oils 83 

Composition. — Properties. — Function  of  Fats  in  Nutrition. 
— Digestibility. — Sources  of  Fats. — Cooking  in  Fats. — Prepar- 
ation of  Fats. 


CONTENTS  •        vii 


CHAPTER  XI 

PAGE 

Milk 90 

Value  as  Food. — Composition. — Digestibility. — The  Care 
of  Milk.— Skim  Milk.— Sour  Milk.— Certified  Milk.— Pas- 
teurized Milk. — Sterilized  Milk. — Condensed  Milk. — Milk 
Powder.— Modified  Milk. — Malted  Milk. — -Milk  in  Cooking — 
Milk  Products. — Butter  and  Cheese. 


CHAPTER  XII 

Eggs 97 

Structure. — Composition  and  Food  Value. — DigestibiUty. — 
Selection  and  Care. — Preparation  and  Cooking. 


CHAPTER  XIII 

Meats 104 

Structure. — Kinds. — Composition. — Digestion  of  Meat. — 
Food  Value  of  Meat. — Selection  of  Meat. — Cooking  of  Meat. — 
Methods  of  Preserving  Meat. — Cuts  of  Beef. — Cuts  of  Veal. — 
Sweetbreads. — Cuts  of  Lamb  and  Mutton. — Cuts  of  Pork. — 
Internal  Organs  Used  as  Food. — Gelatin. 


CHAPTER  XIV 

Poultry  and  Game 114 

Definition. — Composition  and  Food  Value. — Selection. — 
Picking. — Chickens. — Turkeys. — Ducks  and  Geese. — Squab 
and  Guinea  Fowl. — Preparation  and  Cooking  of  Poultry. 


CHAPTER  XV 

Fish 118 

Quality  and  Flavor. — Composition. — Digestibility  of  Fish. — 
How  to  Choose  Fish, — Cooking  of  Fish. — Ways  of  Preserving. 
— Common  Food  Fish. — Specially  Prepared  Fish. — Unusual 
Tyjjes  of  Fish  Recommended  by  the  Bureau  of  Fisheries. — 
Shell  Fish. — Oysters. — Clams. — Mussels. — Lobsters. — Crabs. 
— Shrimps .  — Te  rrapin. 


viii  CONTENTS 

CHAPTER  XVI 

PAGE 

Mineral  Matter 125 

Definition. — Function  in  Body. — Sources  of  Mineral  Matter. 
— Calcium. — Iron. — Phosphorus. — Sodium   Chloride. — Vita- 
mines. — Function  of  Vitamines  in  Body. 

CHAPTER  XVII 

Beverages 129 

Tea. — Composition. — Classes  of  Tea. — Grades  of  Tea. — 
Adulterants  of  Tea. — Coffee. — Preparation  for  Use. — Substitu- 
tion and  Adulteration. — Chocolate  and  Cocoa. — Effect  of  Bev- 
erages on  Body. 

CHAPTER  XVIII 

Condiments  and  Other  Accessories 136 

Value  in  Diet. — Salt. — Vinegar. — Spices. — Flavoring  Ex- 
tracts. 

CHAPTER  XIX 

Food  Requirements  of  the  Body 140 

The  Necessity  for  Food. — Amount  of  Food  Required. — 
Calories. — Computation  of  Energy  Value  of  Foods. — Require- 
ment for  Growth  and  Repair. — Requirement  for  Body  Regula- 
tion. 

CHAPTER  XX 

Food  Combinations  in  Meals 143 

Planning  Meals. — Per  Cent  of  Income  for  Food. — Food  for 
Adults  and  Children. — Cost  of  Food. — Balanced  Meals. — 
Variety  in  Diet. — The  ^Esthetic  Considerations. — Desirable. 
Foods. — ^Food  Combinations. — Suggestions  for  Planning  Meals 
— Sample  Meals  Showing  the  Approximate  Number  of  Cal- 
ories Furnished. 

CHAPTER  XXI 

The  Preservation  of  Foods 156 

Why  Foods  Spoil. — Ways  of  Preserving  Foods. — Canning 
by  the  Open  Kettle  Method.— The  One-Period  Cold  Pack 
Method. — Intermittent  Sterilization. — Use  of  Preservatives. — 
Kinds  of  Preservatives. — Drying  of  Fruits  and  Vegetables. 

Glossary 165 


FOOD 

ITS  COMPOSITION  AND  PREPARATION 


CHAPTER   I 
INTRODUCTORY 


1.  Definition  of  Food. — Food  is  any  substance  which, 
when  taken  into  the  body,  is  capable  of  building  body 
substance,  yielding  energy,  or  regulating  body  processes. 

2.  Classification  of  Foods. — Foods  may  be  classified  as 
organic  and  inorganic.  The  organic  foods,  as  the  name 
implies,  are  derived  from  an  organism,  which  organism  may 
be  a  plant  or  an  animal.  As  organic  foods  serve  the  purpose 
of  replacing  tissues  which  have  been  oxidized  (burned) 
they  themselves  must  be  oxidizable. 

Inorganic  foods  serve  to  replace  tissue  which  has  not 
been  oxidized;  they  are  water  and  mineral  substances  and 
are  not  oxidizable. 

3.  Food  as  a  Source  of  Energy. — A  plant  has  the  power  of 
taking  carbon  dioxide  from  the  air,  and  with  the  aid  of  the 
light  and  heat  of  the  sun,  combining  it  with  water  from  the 
soil,  thus  forming  such  compounds  as  starch,  sugar  and 
protein.  Heat  is  absorbed  during  the  process;  therefore, 
when  these  compounds  are  oxidized  in  the  body,  they 
decompose  into  their  original  constituents,  at  the  same 
time  liberating  the  same  amount  of  heat  as  was  absorbed 
during  their  formation.  This  liberated  heat  is  the  source 
of  all  body  energy. 


While  animals  cannot  make  use  of  such  simple  substances 
as  are  found  in  the  air  and  the  earth,  they  can  use  such 
substances  when  they  have  been  transformed  by  the  plant. 
The  animals,  in  their  turn,  convert  the  simple  substances 
into  more  complex  substances  which  man  designates  as 
animal  food. 

4.  How  Food  is  Like  the  Body  Tissues. — If  food  is  to 
build  body  tissue,  it  must  bear  some  likeness  to  that  tissue. 
As  this  likeness  does  not  lie  in  appearance  it  must  in  com- 
position, and  chemical  analysis  shows  this  to  be  the  case. 
Food  and  the  body  tissues  are  made  up  of  similar  elements 
and  compounds. 

The  elements  are:  Oxygen,  hydrogen,  nitrogen,  carbon, 
sulphur,  phosphorus,  chlorine,  sodium,  potassium,  calcium, 
magnesium,  iron,  fluorine,  silicon,  and  iodine. 

The  compounds  are:  Water,  fat,  carbohydrates,  protein, 
and  mineral  matter.  These  compounds,  when  spoken  of  in 
connection  with  food,  are  called  foodstuffs  and  must  not  be 
confused  with  food  materials,  such  as  eggs,  meat,  cereals,  etc. 

5.  Composition  of  Foodstuffs. — Water  is  composed  of 
the  two  elements  oxygen  and  hydrogen. 

Fat  is  composed  of  the  three  elements  oxygen,  hydrogen, 
and  carbon. 

Carbohydrates,  which  include  starch  and  sugar,  are 
composed  of  the  same  three  elements  that  form  fat,  but  in 
the  carbohydrates  the  oxygen  and  hydrogen  occur  in  the 
proper  proportion  to  form  water. 

Water,  fat,  and  carbohydrates  are  the  first  of  the  great 
foodstuffs  which  the  plant  manufactures  from  the  simple 
inorganic  compounds. 

Proteins  are  the  most  complex  of  all  the  foodstuffs. 
They  contain,  in  addition  to  the  three  elements  found  in 
fats  and  carbohydrates,  other  elements,  the  chief  of  which 
are  nitrogen  and  sulphur.  The  nitrogen  occurs  in  simpler, 
substances  called  amino  acids,  and  these  by  different  com- 
binations form  the  various  proteins. 


INTRODUCTORY  3 

Mineral  Matter  includes  such  chemical  elements  as  iron, 
calcium,  magnesium,  potassium,  sodium,  chlorine,  sulphur, 
and  phosphorus.  Some  of  these  occur  as  elements  while 
others  are  found  only  in  combination ;  some  occur  in  organic 
material  while  others  exist  only  in  their  inorganic  form. 

6.  Tests  for  Foodstufifs. — Water  may  be  detected  in 
food  by  heating  a  small  amount  of  the  food  in  a  test  tube. 
Drops  of  water  will  form  on  the  sides  of  the  tube. 

Starch  may  be  detected  by  adding  to  the  food,  or  a 
solution  of  the  food,  a  few  drops  of  iodine.  The  material 
will  turn  blue  if  starch  is  present. 

Sugar  may  be  detected  by  boiling  a  small  portion  of  the 
food  in  water  and  then  adding  Fehling's  solution.*  A 
reddish  brown  precipitate  is  formed  if  sugar  is  present. 

Fat  may  be  detected  in  the  following  way:  stir  some  of 
the  food  with  ether  or  benzine,  allow  it  to  stand  ten  minutes, 
then  filter  it  and  allow  the  ether  to  evaporate.  The  fat  will 
remain. 

Protein  may  be  detected  by  the  use  of  nitric  acid  and 
ammonia.     The  substance  turns  yellow  if  protein  is  present. 

Mineral  Matter  may  be  detected  by  burning  a  sample  of 
the  food.    The  residue  which  will  not  burn  is  mineral  matter. 

7.  Functions  of  the  Foodstuffs  in  the  Body. — The 
function  of  water  in  the  body  is  to  build  tissue  and  regulate 
body  processes. 

The  chief  function  of  fat  is  to  yield  energy,  but  it  may  be 
stored  in  the  body  as  fatty  tissue. 

The  chief  function  of  carbohydrate  is  to  supply  energy 
to  the  body,  but  it  may  furnish  building  material  also. 

The  chief  function  of  protein  is  to  build  tissue,  but  it 
may  also  furnish  energy. 

The  chief  function  of  mineral  matter  is  to  furnish  build- 
ing material  and  to  regulate  body  processes. 

Vitamines  are  substances  essential  to  growth  and  nerve 
activity. 

♦Fehling's  solution  is  copper  sulphate,  Rochelle  salts,  and  caustic  soda. 


4  FOOD 

8.  The  Means  by  which  Food  is  Made  Available. — Food, 

in  order  to  become  available  to  the  body,  must  undergo 
certain  physical  and  chemical  changes.  These  changes 
are  brought  about  by  such  processes  as  cooking,  digestion, 
absorption,  and  assimilation. 

Cooking  is  the  preparation  of  food  by  the  aid  of  heat. 
Such  foods  as  milk,  eggs,  and  certain  fruits  and  vegetables 
may  be  eaten  without  cooking,  but  this  is  possible  only 
because  they  have  previously  been  subjected  to  a  process 
similar  to  cooking.  In  the  cases  of  the  first  two  the.  heat 
coming  from  the  body  of  the  animal  really  did  the  cooking, 
and  in  the  third  the  heat  from  the  sun  during  the  process 
of  ripening  performed  the  same  operation. 

9.  Purposes  of  Cooking. — Cooking  is  necessary  for  three 
distinct  purposes: 

1.  To  kill  micro-organisms. 

2.  To  make  the  food  more  digestible. 

3.  To  improve  and  develop  flavor  in  the  food. 

10.  Processes  of  Cooking. — The  different  methods  of 
applying  heat  to  food  are  known  as  processes  of  cooking^ 
and  are: 

1.  Boiling. — Cooking  in  boiling  water  or  at  a  temperature 
of  212°  F. 

2.  Broiling. — Cooking  directly  over  or  under  a  flame. 

3.  Pan-hr oiling. — Cooking  on  a  very  hot  frying  pan 
without  any  fat. 

4.  Baking. — Cooking  in  a  hot  oven.  • 

5.  Roasting. — Cooking  in  a  very  hot  oven. 

6.  Frying. — Cooking  in  sufficient  hot  fat  to  cover  the 
food. 

7.  Sauteing. — Cooking  in  a  frying  pah  in  a  small  amount 
of  fat. 

8.  Steaming. — Cooking  over  steam. 

(a)  Dry,  as  in  a  double  boiler. 

(b)  Moist,  as  in  a  steamer. 


INTRODUCTORY 


9.  Stewing. — Cooking  in  water  below  the  boiling-point, 
180°  F. 

10.  Braising  (or  pot  roasting). — A  combination  of  stew- 
ing and  baking. 

11.  Fricasseeing. — A  combination  of  stewing  and  saut^- 
ing. 

11.  Digestion. — Digestion  is  the  process  of  changing 
insoluble  foods  to  soluble.  This 
process  takes  place  in  that  part 
of  the  body  known  as  the  alimen- 
tary canal,  Fig.  1.  This  canal 
measures  from  twenty  to  twenty- 
five  feet  in  length.  Into  this  canal 
is  poured  secretions  from  such 
organs  as  the  salivary  glands,  the 
pancreas,  and  the  liver,  all  of 
which  aid  in  the  work  of  digestion. 

The  parts  of  the  alimentary 
canal  are  the  mouth,  the  oesopha- 
gus, the  stomach,  the  small  in- 
testine, and  the  large  intestine. 

12.  Work  of  the  Alimentary 
Canal. — Each  part  of  the  alimen- 
tary danal  has  its  special  work  to 
do  and  is  furnished  with  mechan- 
ical and  chemical  agents  for  ac- 
complishing its  task.  The  food- 
stuffs are  acted  upon  chemically 
in  different  parts  of  the  canal. 

The  Mouth. — In  the  mouth  all 
food  is  acted  upon  mechanically  by 
the  teeth,  which  grind  it,  and  by 
the  saliva,  which  moistens  it. 
The    starchy   foods    are    further 

acted  upon  chemically  by  an  enzyme  called  ptyalin,  which 
is  found  in  the  saliva,  and  which  has  the  power  of  changing 


Fig.  1. — Front  view  of  the 
digestive  organs. 

a,  c,  e,  colon; 

d,  duct  of  the  gall  bladder; 

g,  gall  bladder; 

i,  small  intestine; 

I,  V,  liver; 

o,  e,  esophagus; 

p,  n,  pancreas; 

st,  stomach. 


6  FOOD 

the  insoluble  starch  into  a  form  of  sugar  called  maltose. 
From  the  mouth  the  food  passes  through  the  CEsophagus 
into  the  stomach. 

The  Stomach. — In  the  stomach  the  food  is  kept  in  motion 
by  the  muscular  walls,  which  by  their  churning  bring  all  the 
food  in  contact  with  the  gastric  juice.  The  connective  tissue 
of  meat  is  here  dissolved,  and  the  meat  fibres  loosened. 
The  walls  of  fat  cells  are  also  dissolved,  as  well  as  certain 
mineral  salts  such  as  phosphate  of  lime.  The  protein  foods 
are  acted  upon  chemically  by  two  enzymes  found  in  the 
gastric  juice.  The  first  of  these,  pepsin,  has  the  power  of 
changing,  in  the  presence  of  hydrochloric  acid,  the  non- 
dialyzable  proteins  into  dialyzable  peptones.  The  second 
enzyme,  rennin,  coagulates  the  caseinogen  of  milk,  which  is 
a  necessary  change  before  the  milk  can  be  digested  by  the 
pepsin.  It  is  thought  by  some  that  a  third  enzyme  is 
present  in  the  gastric  juice  which  acts  upon  emulsified  fats. 

After  the  food  has  remained  in  the  stomach  from  one 
to  five  hours  the  mass  is  reduced  to  a  grayish,  semi-liquid 
state  in  which  condition  it  is  known  as  chyme,  and  begins  to 
pass  in  small  amounts  into  the  small  intestine. 

The  Small  Intestine. — Here  the  food  comes  in  contact 
with  the  pancreatic  juice,  an  important  digestive  fluid  fur- 
nished by  the  pancreas;  with  the  bile,  a  fluid  manufactured 
by  the  liver;  and  with  the  intestinal  juice,  which  is  secreted 
by  the  glands  that  line  the  small  intestine. 

Pancreatic  juice  contains  three  enzymes:  trypsin, 
amylopsin,  and  steapsin  or  lipase.  The  trypsin  acts  upon 
any  proteins  which  may  have  escaped  the  action  of  the 
pepsin;  the  amylopsin  acts  upon  undigested  starch,  changing 
it  into  maltose  even  more  quickly  than  the  ptyalin  can; 
and  the  lipase  serves  to  emulsify  fats  and  to  some  extent 
break  them  up  into  fatty  acids  and  glycerin.  The  action 
of  the  bile  is  to  help  in  the  absorption  of  fats  and  by  its 
alkalinity  to  counteract  the  acidity  of  the  chyme. 

The  intestinal  juice  has  no  special  action  except  upon  the 


INTRODUCTORY  7 

sugars,  converting  maltose  into  grape  sugar.  After  the 
food  has  been  acted  upon  by  the  various  fluids  in  the  small 
intestine,  it  changes  from  acid  chyme  into  alkaline  chyle,^ 
in  which  condition  much  of  it  is  absorbed.  Food  which  is 
by  nature  indigestible,  or  which  has  been  made  so  by  im- 
proper cooking,  passes  from  the  small  intestine  into  the 
large. 

The  Large  Intestine. — While  the  large  intestine  has  no 
enzyme  of  its  own,  the  walls  furnish  a  fluid  which  helps  to 
complete  digestive  changes  which  have  already  begun. 
Absorption  takes  place  here  to  some  extent  and  the  residue 
of  the  food  is  here  evacuated  from  the  body. 

13.  Absorption. — Much  of  the  digested  food  is  absorbed 
from  the  small  intestine.  All  the  digested  carbohydrate 
and  protein  foods  are  taken  up  by  the  epithelial  cells,  and 
the  fats  are  taken  by  the  lacteals  or  lymph  vessels.  These 
are  tiny  thread-like  tubes  which  convey  the  fats  to  the 
thoracic  duct,  lying  in  front  of  and  to  one  side  of  the  back 
bone.  From  there  the  fats  are  poured  into  the  blood  stream. 
The  other  foods  are  absorbed  by  the  blood  capillaries  which 
carry  them  by  the  portal  system  to  the  liver  and  thence 
to  the  heart  to  be  sent  with  the  blood  to  nourish  all  parts 
of  the  body. 

14.  Assimilation. — Assimilation  is  the  process  by  which 
each  part  of  the  body  works  over  into  its  own  substance 
material  derived  from  the  food  eaten. 


CHAPTER  II 
WATER 

15.  Composition. — In  composition  water  is  the  simplest 
of  the  foodstuffs,  as  it  is  made  up  of  but  two  elements, 
oxygen  and  hydrogen. 

While  water  is  not  capable  of  yielding  energy  because 
it  contains  no  unoxidized  hydrogen,  its  function  in  the  body 
is  of  such  vital  importance  that  it  must  be  considered  most 
essential. 

16.  Kinds  of  Water. — Water  is  hard  or  soft,  according 
to  the  amount  of  mineral  matter  present  in  it.  The  hard- 
ness of  some  water  is  due  to  the  presence  of  lime  salts  which, 
if  in  excess,  may  interfere  with  the  general  health.  These 
salts  may  be  eliminated  by  boiling  the  water.  This  process 
will  drive  off  the  carbon  dioxide  which  holds  the  carbonates 
in  solution  and  the  lime  will  be  precipitated.  Boiling  also 
removes  organic  impurities.  To  remove  the  insipid  taste 
which  results  from  boiling,  the  water,  after  having  been 
cooled,  may  be  shaken  vigorously. 

17.  Functions  of  Water  in  the  Body. — Water  serves  as 
building  material,  two-thirds  of  the  body  weight  being  made 
up  of  water.  It  gives  firmness  and  elasticity  to  the  tissues 
and  constitutes  four-fifths  of  the  blood. 

Water  acts  as  a  great  solvent  in  the  body,  carries  nutri- 
ment to  all  the  tissues,  and  conveys  the  effete  matter  to  the 
organs  through  which  it  is  eliminated.  It  also  keeps  the 
fluids  of  the  body  in  their  liquid  state. 

Water  acts  as  a  body  regulating  substance  and  a  stimu- 
lant; particularly  is  it  important  in  the  digestive  tract 
where  experiment  has  shown  that  the  production  of  hydro- 


WATER  9 

chloric  acid  in  the  stomach  is  greatly  accelerated  after 
drinking  a  glass  of  water.  There  is  proof  also  that  water 
aids  digestion  by  acting  as  a  diluent  on  certain  digestive 
juices,  thereby  increasing  their  solvent  power. 

18.  Amount  of  Water  Required. — The  amount  of  water 
which  the  body  requires  varies  and  is  dependent  upon  the 
surrounding  temperature,  the  amount  of  muscular  activity 
indulged  in,  and  the  nature  of  the  food  eaten. 

One  of  the  most  prevalent  dietary  errors  is  the  use  of 
too  little  water  in  the  diet.  The  daily  requirement  is 
approximately  four  pints.  About  one-fourth  this  amount 
is  obtained  from  the  food  eaten. 

19.  Water  in  Food. — All  foods,  no  matter  how  dry  they 
may  appear  to  be,  contain  some  water,  and  some  vegetables, 
such  as  asparagus,  contain  as  high  as  94  per  cent  of  water. 
The  keeping  quality  of  all  foods  depends  largely  upon  the 
amount  of  water  they  contain.  Foods  containing  more  than 
20  per  cent  of  water  cannot  be  stored,  owing  to  their  tendency 
to  mold.  Flour  or  cereals  that  are  to  be  kept  any  length  of 
time  must  not  contain  higher  than  10  to  12  per  cent  of 
water. 

TABLE  I.— FOODS  HAVING  A  HIGH   WATER  CONTENT 

Weight  in  ounces  of  the  100-calorie  portion 

Watermelon 28|  ozs. 

Cucumbers 20^  ozs. 

Celery 19    ozs. 

Lettuce I85  ozs. 

Muskmelon 18    ozs. 

Asparagus 16    ozs. 

Rhubarb 15j  ozs. 

Tomatoes 14^  ozs. 

Egg  plant 14|  ozs. 

Spinach 14f  ozs. 

Radishes 12    ozs. 

Peaches 10§  ozs. 

Cabbage 11^  ozs. 

Buttermilk 9|  ozs. 


10  FOOD 

20.  Water  as  a  Cooking  Medium. — Water  is  necessary 
in  the  preparation  of  food  and  for  this  purpose  soft  water  is 
preferable. 

All  foods  are  not  cooked  at  the  same  temperature,  and 
the  degree  of  heat  must  be  adapted  to  the  food  in  question. 
If  water  is  raised  slowly  to  the  boiling-point,  the  following 
changes  will  be  observed.  Tiny  bubbles  will  appear  on  the 
bottom  and  sides  of  the  vessel  but  will  break  before  reaching 
the  surface.  These  bubbles  are  caused  by  the  air  and  gases 
which  have  been  confined  in  the  water  being  driven  off 
by  the  heat  (it  is  the  loss  of  these  which  causes  the  flat 
taste  of  boiled  water).  As  the  temperature  rises,  the 
bubbles  in  the  water  will  become  larger  and  more  nearly 
spherical  and  will  reach  the  surface  before  the}^  break.  At 
this  point  the  water  is  said  to  boil,  and  a  thermometer  intro- 
duced into  it  will  register  212°  F.  or  100°  C;  for  an  open 
vessel  at  sea  level,  no  matter  how  rapidly  the  water  may  boil, 
the  temperature,  under  ordinary  conditions,  will  rise  no  higher, 
the  surplus  heat  being  used  to  convert  the  water  into  steam. 

21.  Raising  the  Boiling-point. — The  boiling-point  of 
water  may  be  raised:  (1)  By  increasing  the  pressure — for 
example  boiling  in  a  confined  space,  as  in  a  steam  boiler 
under  a  pressure  of  five  pounds  of  steam,  when  the  water 
will  not  boil  until  it  reaches  227°  F. 

(2)  By  increasing  the  density — for  example  a  very 
strong  salt  solution  will  not  boil  until  it  reaches  226°  F.,  and 
a  sugar  solution  may  have  a  boiling-point  between  215° 
and  350°  F. 

22.  Lowering  the  Boiling-point. — The  boiling-point  of 
water  is  lower  than  212°  F.  when  the  pressure  of  the  atmos- 
phere is  less  than  fifteen  pounds  to  the  square  inch.  In  high 
altitudes,  as  in  Denver,  Colorado,  water  boils  at  a  tempera- 
ture of  202°  F.,  and  on  some  points  in  the  Himalaya  Moun- 
tains it  boils  at  a  temperature  as  low  as  180°  F.  Under 
such  conditions  it  is  difficult  to  properly  cook  foods  which 
require  a  high  temperature. 


WATER  11 


EXPERIMENTS 


Experiment  1.     To  Show  the  Effect  of  Boiling  on  Hard  Water. — 

Half  fill  a  beaker  with  lime  water.  Blow  through  a  glass  tube  into  the 
water  until  it  loses  its  cloudy  appearance  and  becomes  clear.  (This 
shows  that  excess  of  carbon  dioxide  keeps  lime  in  solution.)  Boil  this 
water  and  notice  the  deposit  of  carbonate  of  lime  on  the  bottom  and 
sides  of  the  beaker.  Add  a  little  acid  to  this  deposit  and  observe  the 
effervescence  that  takes  place. 

Half  fill  an  evaporating  dish  with  water  from  the  faucet.  Let  it 
evaporate  over  a  Bunsen  burner,  and  test  the  residue  as  in  the  above 
experiment. 

Experiment  2.  To  Show  Effect  of  Density  on  the  Boiling-point 
of  Water. — (a)  Boil  water,  taking  the  temperature. 

(b)  Boil  a  saturated  salt  solution  and  take  the  temperature. 

Experiment  3.  To  Show  the  Rapidity  of  Evaporation. — Put  the 
same  amount  of  water  in  each  of  two  vessels;  one  deep  and  exposing 
but  little  surface,  the  other  shallow  and  exposing  a  large  surface. 
Boil  both  slowly  and  observe  in  which  vessel  the  water  boils  away  first. 


CHAPTER  III 
CARBOHYDRATE  IN  THE  FORM   OF   SUGAR 

23.  Composition. — Carbohydrate  foodstuffs  are  a  com- 
bination of  the  three  elements,  carbon,  hydrogen,  and 
oxygen.  The  hydrogen  and  oxygen  are  present  in  the  com- 
mon foods  of  this  class  in  the  proportion  to  form  water. 

For  purposes  of  more  thorough  study,  the  carbohydrates 
are  sometimes  divided  into  three  main  groups  according 
to  their  molecular  weight. 

Group  1.  Monosaccharides. — These  comprise  simple 
sugars  which  cannot  be  split  into  other  sugars  of  the  same  or 
simpler  form.    They  are:  glucose,  fructose,  and  galactose. 

Group  2.  Disaccharides. — These  comprise  the  complex 
sugars  which  may  be  split  into  two  simple  sugars.  They 
include:  sucrose,  maltose,  and  lactose. 

Group  3.  Polysaccharides. — These  are  substances  which 
yield  an  unknown  number  of  simple  sugars.  Included  in 
the  group  are:  starch,  dextrin,  arid  glycogen. 

24.  Monosaccharides. — Monosaccharides  are  soluble  crys- 
talline substances  which  are  absorbed  into  the  blood  stream 
without  further  change. 

The  members  of  this  group  have  the  common  formula 
of  C6Hi206-  The  source  and  distinguishing  characteristics 
of  each  of  the  simple  sugars  will  be  considered  in  turn. 

Glucose,  sometimes  called  dextrose,  is  the  most  important 
of  the  simple  sugars  as  it  is  in  this  form  that  sugar  appears 
in  the  blood.  Normal  blood  contains  about  0.1  per  cent 
of  glucose  which  is  being  burned  continually  to  produce 
body  energy.  Any  surplus  of  glucose  absorbed  from  the 
digestive  tract  is  stored  in  the  body  as  glycogen,  which  is 

12 


CARBOHYDRATE  IN  THE  FORM  OF  SUGAR     13 

in  turn  reconverted  into  glucose  to  be  burned  as  needed  for 
energy. 

Fructose,  or  levulose,  like  glucose,  is  found  as  such  in 
some  plants  and  vegetables  and  in  large  quantities  in  honey. 

Galactose  is  of  considerable  importance  in  nutrition 
since  it  is  a  product  of  the  digestion  of  milk.  It  is  utilized 
in  the  formation  of  glycogen  in  the  liver. 

25.  Disaccharides. — The  disaccharides  are  complex  sugars 
having  a  formula  of  C12H22O11.  They  are  soluble  sub- 
stances and  are  changed  to  simple  sugars  in  the  process  of 
digestion. 

Sucrose,  or  cane  sugar,  is  found  in  nature  in  the  juices 
of  certain  plants.  Sugar  cane  and  the  sugar  beet  yield 
large  quantities  of  sucrose  and  form  the  chief  sources  of  the 
commercial  sugars. 

Maltose  is  formed  from  starch  by  the  action  of  acids 
and  enzymes.  Maltose  also  occurs  in  malt  and  malt 
extracts. 

Lactose,  or  sugar  of  milk,  is  found  in  the  milk  of  mam- 
mals. It  is  obtained  for  commercial  use  from  the  whey 
of  milk  after  the  curd  has  been  removed  in  the  making  of 
cheese.  Lactose  is  not  easily  fermented  and  is,  therefore, 
used  in  modifying  cow's  milk  for  infants. 

26.  Polysaccharides. — Polysaccharides  are  complex  sub- 
stances.    They  are  considered  at  length  in  Chapter  IV. 

27.  Functions  of  Sugar  in  Nutrition. — (1)  As  a  Source  of 
Energy.  The  chief  function  of  sugar  in  nutrition  is  to  supply 
energy  to  the  body.  It  is  especially  well  adapted  for  use 
as  an  energy  producer  because  it  is  ready  for  almost  immedi- 
ate absorption  into  the  blood  stream.  Theoretically,  sugar 
is  not  essential  in  a  modern  dietary  where  starches  are 
used,  since  all  starches  are  changed  to  sugar  in  the  process  of 
digestion.  It  is  recommended  that  sugar  be  used  in  small 
amounts  for  flavoring  and  to  give  variety  to  the  diet  rather 
than  as  a  source  of  energy. 

(2)  As  a  building  material.     Sugar,  in  the  form  of  galac- 


14  FOOD 

tose,  is  found  in  the  growth  stimulating  part  of  the  nerve 
cells.  An  excess  of  sugar  in  the  system  is  converted  into 
fat  and  stored  in  the  body  substances. 

(3)  As  a  body  regulating  substance.  Without  carbo- 
hydrate, fat  cannot  burn  normally  in  the  body.  In  other 
words,  fat  must  burn  in  a  flame  of  carbohydrate.  Unless 
the  calories  furnished  by  carbohydrate  exceed  those  furnished 
by  fat,  an  abnormal  condition  of  nutrition  known  as  acidosis 
is  liable  to  obtain.  This  condition  is  caused  by  the  presence 
of  acid  in  the  body  substances  rather  than  in  the  blood. 

28.  Digestion  of  Sugar. — There  is  no  ferment  or  digestive 
juice  in  the  body  that  acts  upon  the  monosaccharides, 
glucose,  fructose,  and  galactose.  These  substances  are 
absorbed  from  the  intestines  without  further  change,  and 
pass  into  the  portal  vein  by  which  they  are  carried  to  the 
liver.  Some  of  this  sugar  is  changed  to  glycogen  and 
stored  in  the  liver,  and  the  rest  is  passed  on  through  the 
blood  stream  to  the  tissues,  where  it  is  burned  to  CO2  and 
H2O  to  yield  energy  for  work,  or  is  stored  in  the  muscular 
tissue  as  glycogen  or  fat. 

In  the  case  of  the  complex  sugars  or  disaccharides,  there 
is  no  digestive  action  in  the  mouth  or  in  the  stomach,  but 
the  intestinal  membrane  secretes  a  substance  known  as 
succus  entericus,  or  intestinal  juice,  containing  the  three 
enzymes,  sucrase,  maltase,  and  lactase,  which  act  in  turn 
upon  the  disaccharides  and  change  these  double  sugars 
into  two  single  sugars  as  follows: 

Sucrose  +  sucrase  =  glucose  and  fructose. 
Maltose +maltase  =  glucose  and  glucose. 
Lactose  +  lactase  =  glucose  and  galactose. 

The  processes  of  absorption  and  assimilation  as  glucose, 
fructose,  and  galactose  go  on  with  but  little  tax  on  the 
digestive  organs. 

The  polysaccharides  are  taken  through  a  much  more 
complicated  process  of  digestion,  but  finally  reach  the  same 


CARBOHYDRATE  IN  THE  FORM  OF  SUGAR     15 

end  and  serve  the  same  purpose  in  the  general  scheme  of 
nutrition.  The  digestion  of  starch  probably  continues  for  a 
time  in  the  stomach,  or  until  the  reaction  of  the  contents 
has  become  acid,  and  then  ceases  until  the  small  intestine 
is  reached.  Here  is  found  another  enzyme,  secreted  by  the 
pancreas  and  known  as  amylopsin,  which  completes  the 
change  of  all  starch  not  already  taken  care  of  by  the  ptyalin 
in  the  mouth  to  maltose,  a  double  sugar. 

29.  Commercial  Sugar. — The  commercial  forms  in  which 
sugar  may  be  obtained  are  more  or  less  familiar  to  all.  Cut 
sugar  is  undoubtedly  the  purest  form  in  which  cane  sugar 
may  be  purchased.  Granulated  sugar  is  the  most  desirable 
for  general  use.  There  is  very  little  difference  chemically 
between  sugar  made  from  sugar  cane  and  that  made  from 
the  sugar  beet,  but  many  housewives  prefer  the  cane  sugar 
for  cake  and  candy  making. 

30.  Molasses. — Molasses  is  the  liquid  left  after  the  sugar 
crystals  are  removed  in  the  manufacture  of  sugar.  It 
contains  a  considerable  quantity  of  sucrose  and  many  of 
the  other  constituents  of  the  sugar  cane  juice. 

The  adoption  of  modern  methods  in  the  making  of  sugar 
has  had  a  tendency  to  increase  the  amount  of  sucrose 
removed  by  crystallization  and  to  decrease  the  amount  of 
molasses  remaining,  as  well  as  to  lower  its  sugar  content. 
The  molasses  of  the  present  time  is  inferior  in  sweetening 
power  and  in  other  characteristics  to  that  formerly  produced. 

31.  Maple  Sugar  and  Syrup. — By  evaporating  the  sap 
of  the  sugar  maple  until  more  than  half  of  the  water  has 
been  removed  and  the  product  is  of  proper  consistency, 
maple  sugar  and  maple  syrup  are  obtained.  Maple  syrup 
is  highly  prized  for  table  use.  The  unadulterated  article  is 
expensive  and  difficult  to  obtain.  It  is  not  uncommon  to 
find  maple  syrup  adulterated  with  a  solution  of  refined  cane 
sugar,  since  the  latter  is  less  expensive  than  the  pure  maple 
sugar. 

32.  Honey. — Pure  honey  consists  of  a  mixture  of  cane, 


16  FOOD 

grape,   and   fruit   sugars,   collected  from   the   flowers   and 
modified  by  the  bees. 

In  addition  to  sugar  and  water,  honey  contains  a  very 
slight  amount  of  protein,  1  per  cent  of  mineral  matter, 
and  certain  volatile  oils  to  which  are  due  the  pecuUar  odor 
and  flavor.  The  differences  in  color  and  flavor  are  attrib- 
uted to  the  characteristic  nectars  in  the  different  flowers 
upon  which  the  bees  feed.  Clover  honey  is  considered 
far  superior  to  the  dark  colored  and  strong  flavored  article 
commonly  supposed  to  be  made  from  buckwheat  blossoms. 

Honey,  as  has  been  stated,  contains  more  fructose 
than  glucose  and  is  therefore  more  readily  absorbed  into  the 
blood  stream  than  cane  sugar.  It  is  also  less  liable  to  cause 
digestive  disturbances  due  to  fermentation.  One  cup  of 
honey  is  equal  to  one  cup  of  cane  sugar  in  sweetening  power 
and  may  be  used  in  place  of  sugar.  Honey  is  also  a  sub- 
stitute for  molasses  and  may  be  used  in  any  way  that 
molasses  is  used.  It  must  be  remembered,  however,  in 
using  honey  that  the  acidity  of  honey  is  about  one  half 
that  of  molasses  and  only  one-fourth  teaspoonful  of  soda 
is  required  to  one  cupful  of  honey  to  neutralize  the  acid. 
Like  maple  syrup,  strained  honey  is  easily  adulterated  with 
sugar  syrups. 

33.  Effects  of  Cooking  Sugar. — The  boiling  of  cane  sugar 
and  water  together,  called  the  hydrolysis  of  sugar,  changes 
it  into  equal  parts  of  glucose  and  fructose. 

Cane  sugar,  when  cooked  for  a  long  time  with  acid 
fruits,  is  converted  into  grape  sugar  or  glucose  and  thereby 
loses  about  one  third  of  its  sweetening  power.  This  is  the 
reason  why  the  sugar  should  be  added  to  jams,  jeUies,  and 
sauces  made  from  acid  fruits  when  the  cooking  process  is 
nearly  completed. 

Cane  sugar  cooked  alone  is  changed  first  to  barley 
sugar,  then  to  caramel,  and  finally  to  carbon.  When  the 
sugar  is  melted  and  changed  to  a  light  brown  color,  it  has 
made  the  first  change  and  is  known  as  barley  sugar.    As  the 


CARBOHYDRATE  IN  THE  FORM  OF  SUGAR     17 

melted  sugar  is  heated  to  a  temperature  of  350°  F.  this  brown 
hquid  is  converted  into  a  non-crystalUzable  fluid  having  a 
sUghtly  bitter  but  pleasant  taste,  which  indicates  that  it 
has  reached  the  caramel  stage.  This  caramel  is  used  as  a 
flavoring  substance  for  creams  and  sauces  and  to  give  color 
to  soup  stock.  Because  of  its  mildness  caramel  is  frequently 
recommended  as  a  desirable  flavoring  in  invalid  cookery. 

Carbon,  which  is  the  next  step  after  cararrxel,  is  the  final 
stage  in  the  cooking  of  sugar.     It  is  the  burned  product. 

Table  II  will  be  found  a  valuable  aid  in  the  preparation  of 
icings  and  caramel  and  in  candy  making  when  a  chemical 
thermometer  is  used. 

TABLE  II 

Stages  in  Cooking  Sugar 

Small  thread '.  215°  F. 

Large  thread 217"  F. 

Pearl 220°  F. 

Blow.... 230°  F. 

Feather 232°  F. 

Softball 238°  F. 

Hardball 248°  F. 

Crack 310°  F. 

Caramel 350°  F. 

EXPERIMENTS 

Experiment  1. — Compare  cane  sugar  and  glucose  as  to:  (a)  struc- 
ture; (6)  solubility;  (c)  taste. 

Experiment  2. — Test  different  kinds  of  sugar  with  FehUng's  solu- 
tion and  state  the  results  of  your  tests. 

SUGGESTIONS  FOR  LABORATORY  PRACTICE 

In  connection  with  the  study  of  the  text  of  the  preceding  chapter 
make: 

Cake  icing.     Use  this  on  Marguerites. 

Candy,  and  compare  the  cost  of  home-made  with  factory  candy. 

Caramel  sauce. 


CHAPTER  IV 


CARBOHYDRATE   IN  THE   FORM   OF  STARCH 


34.  Composition. — Starch,  which  is  made  up  of  the  three 
elements  carbon,  oxygen,  and  hydrogen,  is  the  most  important 
of  that  class  of  carbohydrates  known  as  the  polysaccharides. 
Not  only  is  it  important  as  a  food  substance,  but  from  it 
is  made  dextrin  or  British  gum,  <;ommercial  glucose,  and 
other  products.  \ 

35.  Source  and  Structure. — Starch  is  formed  in  all 
plants.     It  is  the  form  in  which  the  plant  stores  its  food 

for  future  consumption  and  is  confined 
in  tiny  sacs  or  cells.  The  seeds,  roots, 
tubers,  and  bulbs  are  the  storage  points. 
If  examined  under  the  microscope,  the 
starch  is  seen  to  be  in  the  form  of 
minute  granules  or  grains  which  differ 
in  size  and  shape  according  to  the 
source  from  which  they  come.  The 
grains  in  potato  starch.  Fig.  2,  are 
relatively  large,  being  3^^  of  an  inch 
in  diameter  and  shaped  like  a  kidney 
bean.  The  grains  of  wheat  starch  are  small,  totTo  of  an 
inch  in  diameter.  The  walls  of  the  cells  are  composed  of 
cellulose.  Starch  is  obtained  commercially  from  corn, 
potatoes,  and  wheat.  Glucose,  as  has  been  stated,  is  pro- 
duced from  starch  by  subjecting  it  to  the  action  of  acids. 
Dextrin  and  maltose  are  intermediate  products  of  this 
action. 

36.  Food  Value. — Starch  from  different  sources  forms 

18 


Fig.  2. — Grains  of 
potato  starch. 


CARBOHYDRATE  IN  THE  FORM  OF  STARCH    19 

a  large  part  of  our  diet,  and  because  it  can  be  manufactured 
by  the  plant  from  carbon  dioxide  and  water,  it  is  an  inex- 
pensive product. 

As  the  starch  in  its  natural  state  is  not  soluble  and  there- 
fore cannot  be  made  available  to  the  body,  it  must  be 
changed  chemically  during  the  process  of  digestion.  This 
change  is  brought  about  by  the  action  of  certain  enzymes 
found  in  the  mouth,  pancreatic,  and  intestinal  juices.  The 
effect  of  their  action  is  to  change  the  starch  first  into  dex- 
trin, then  into  maltose  and  finally  into  glucose,  in  which 
latter  form  it  is  absorbed  into  the  blood  stream.  The  ease 
with  which  these  changes  are  affected  depends  greatly 
upon  the  source  from  which  the  starch  comes;  potato 
starch  is  supposed  to  be  acted  upon  much  more  readily 
than  starch  from  cecals.  Rice  starch  is  comparatively 
easy  of  digestion,  though  this  ease  may  possibly  be  attrib- 
uted to  the  small  amount  of  cellulose  present. 

37.  Functions  of  Starch  in  the  Body.::— While  the  chief 
function  of  starch  in  the  body  is  to  yield  energy,  this  is  by 
no  means  its  only  function.  Starch  plays  a  most  important 
part  in  the  construction  of  body  tissue,  appearing  as  it 
does  in  small  quantities  in  the  nucleo-protein  of  all  proto- 
plasmic tissue. 

Starch  also  acts  as  a  body  regulator.  Owing  to  its 
high  oxygen  content  and  the  ease  with  which  this  oxygen 
may  be  liberated,  it  furnishes  an  excellent  method  of  con- 
veying this  element  to  the  various  tissues.  Starch,  because 
of  its  non-stimulating  and  colloidal  nature,  protects  the 
delicate  walls  of  the  intestines  from  the  action  of  the  more 
irritating  crystalloids  or  sugars. 

The  body  shows  a  decided  preference  for  starch  as  a 
source  of  energy,  and  the  over  consumption  of  this  sub- 
stance is  not  attended  by  the  harmful  results  which  follow 
over  indulgence  in  other  foodstuffs.  When  more  starch 
is  eaten  than  the  body  requires,  it  is  stored  as  glycogen 
and  later  as  fatty  tissue,  or  when  not  stored,  it  is  completely 


20  FOOD 

oxidized  to  carbon  dioxide  and  water  and  eliminated  through 
the  lungs  a^id  kidneys. 
.        38.  Test  for  Starch. — The  presence  of  starch  in  a  sub- 
/   stance  may  be  detected  by  the  use  of  iodine  which,  when 
/     added  to  a  solution  of  starchy  gives  a  blue  reaction. 
V  39.  The  Cooking  of  Starch. — Although  there  is  at  present 

some  question  as  to  the  desirability  of  the  high  temperature 
and  the  long  cooking  popularly  supposed  to  be  a  necessary 
preliminary  to  the  proper  digestion  of  starch,  the  superior 
/  flavor  of  thoroughly  cooked  starch  over  that  of  the  under- 
(  cooked  offers  a  strong  plea  for  long  cooking. 

Starch  will  not  dissolve  in  cold  water  unless  modified 

/      chemically;    neither  does  cold  water  affect  the  starch  granule. 

Hot  water  at  first  merely  causes  the  starch  grains  to 

/  swell,  thereby  stretching  the  cellulose  covering  until  so  thin 

/    that    the   water   will   pass  through.     Prolonged  action    of 

I     boiling  water  brings  about  chemical  changes  which  result 

in  a  soluble  substance. 

Owing  to  its  physical  properties,  starch  can  be  used  as  a 
thickening  substance,  and  for  this  purpose,  it  comes  in  the 
form  of  a  white,  glistening  powder.  When  so  used,  it  should 
be  mixed  with  a  cold  liquid,  with  sugar,  or  with  fat  before 
adding  it  to  a  hot  liquid.  These  substances  separate  the 
j  starch  grains  so  that  the  hot  liquid  reaches  all  the  grains 
j  at  the  same  time,  causing  them  to  swell  uniformly  and 
Y    produce  a  smooth,  gelatinous  mass  free  from  lumps. 

40.  Cellulose. — Cellulose  is  classed  with  starch  as  a 
carbohydrate,  and  is  the  substance  which  forms  the  cell 
walls  in  all  plants  as  well  as  the  frame  work  of  the  plant. 
The  amount  of  cellulose  present  varies  in  different  parts 
of  the  plant  and  at  different  stages  of  the  plant's  growth. 
It  is  more  abundant  in  old  than  in  young  plants.  The 
increased  difficulty  of  digesting  vegetable  foods  as  compared 
to  animal  food  is  attributed  to  the  presence  of  cellulose 
which,  by  enclosing  the  nutrients  in  its  fibrous  envelope, 
prevents  the  free  access  of  the  digestive  juices. 


CARBOHYDRATE  IN  THE  FORM  OF  STARCH    21 

41.  Digestion  and  Food  Value  of  Cellulose. — While  some 
animals  can  digest  cellulose,  the  human  digestive  tract  is 
furnished  with  no  enzyme  for  this  purpose.  The  cellulose 
from  young  plants  is  sometimes  digested  in  the  human 
organism,  but  this  is  brought  about  by  the  action  of  intes- 
tinal bacteria,  the  result  being  probably  the  formation 
of  sugar  that  may  yield  energy. 

Cellulose  cannot  be  regarded  as  having  much  food  value, 
but  it  does  fulfill  a  mission  in  giving  a  certain  amount  of. 
bulk  to  the  food  and  acting  as  a  stimulant  to  peristaltic 
action.  The  virtue  attributed  to  the  cellulose  present  in 
certain  whole  grains  is  now  questioned,  and  the  theory  is 
advanced  that  the  stimulating  properties  of  the  grains  may 
be  due  to  the  salts  found  in  the  grain  covering  rather  than 
to  the  covering  itself. 

42.  Dextrin. — Dextrin  is  made  from  starch  which  has 
been  subjected  to  a  high  degree  of  dry  heat,  2C0°  C, 
and  also  by  heating  starch  with  dilute  acid.  It  is  soluble 
in  water  and  is  more  digestible  than  starch,  having  taken 
one  step  towards  the  formation  of  sugar.  This  fact  accounts 
for  the  increased  digestibility  of  the  crust  of  bread,  over  the 
crumb,  and  of  crisp  toast  over  plain  bread. 

43.  Glycogen. — Glycogen,  sometimes  called  ''animal 
starch,"  is  the  form  of  starch  found  stored  in  the  liver  and 
muscles  of  the  body.  After  meals,  when  there  is  a  specified 
amount  of  glucose  in  the  blood  of  the  portal  vein  and 
sufficient  oxygen  is  present,  the  liver  changes  glucose  (sugar) 
into  glycogen  and  holds  it  until  called  for  by  the  tissues. 
Later  on,  however,  the  liver  changes  some  of  this  glycogen 
back  into  sugar  in  order  to  provide  oxygen  for  its  own 
respiration. 

44.  Less  Familiar  Forms  of  Starch. — (1)  Tapioca  is 
derived  from  a  plant  of  the  cassava  variety  belonging  to 
the  milk  weed  family.  These  plants  are  poisonous  owing 
to  the  natural  development  in  them  of  prussic  acid.  This, 
however,   is  a  volatile  substance,   and  when  the  cassava 


22  FOOD 

root  is  heated  or  boiled  or  even  subjected  to  the  direct 
rays  of  the  sun  for  a  few  hours,  most  of  the  poisonous  ma- 
terial disappears. 

The  tapioca  is  prepared  by  grinding  the  root  of  the  plant, 
then  washing  it  in  water  and,  while  the  starch  is  still  satu- 
rated with  moisture,  subjecting  it  to  a  low  degree  of  heat 
which  is  gradually  increased  until  the  starch  grains  are 
disintegrated  into  a  firm,  gelatinous  mass.  The  heat  is 
then  continued  at  a  suitable  temperature  until  all  the 
moisture  is  evaporated.  To  this  process  is  due  the  ease 
with  which  tapioca  is  cooked  and  digested. 

(2)  Sago  or  Palm  Starch  is  made  from  the  pith  of  the 
sago  palm.     It  closely  resembles  tapioca. 

(3)  Arrowroot  is  so  named  from  the  fact  that  the  natives 
in  the  countries  where  it  grows  use  the  bruised  rhizomes 
of  the  plant  as  a  poultice  for  poisoned  arrow  wounds.  The 
starch  from  arrowroot  has  greater  thickening  properties 
than   starch   from  other   sources. 

EXPERIMENTS 

Experiment  1.  Potato  Starch. — Grate  a  raw  potato  into  a  piece 
of  cheese-cloth,  squeeze  out  all  water  and  wash  the  contents  of  the  cloth 
thoroughly  in  cold  water.  Allow  the  water  to  clear,  pour  off  the 
clear  Uquid,  and  dry  the  residue  at  a  temperature  of  70°  C.  in  a  water 
bath.  Test  a  small  portion  of  the  residue  with  iodine.  Use  one 
teaspoonful  or  this  starch  to  thicken  J  cup  of  liquid.  Use  one  tea- 
spoonful  of  corn  starch  to  thicken  j  cup  of  liquid.  Compare  the  thick- 
ening properties  of  potato  starch  and  corn  starch.  Dry  the  fibrous 
substance  left  in  the  cloth  to  show  the  cellulose. 

Experiment  2.  Effect  of  Boiling  Water  on  Dry  Starch. — Pour 
boiling  water  on  dry  starch  and  observe  the  effect.  Break  open  and 
examine  the  lumps  formed. 

Experiment  3.  Effect  of  Boiling  Water  and  Stirring  upon  Starch. — 
(a)  Mix  two  tablespoonfuls  of  starch  with  two  tablespoonfuls  of  cold 
water.  Add  I  cup  of  boiling  water,  stirring  constantly.  Note  the 
effect. 

(6)  Proceed  as  above,  using  one  tablespoonful  of  sugar  in  place 
of  cold  water.     Add  boiling  water.     Note  the  effect. 

(c)  Proceed  as  in  (a),  using  two  tablespoonfuls  of  fat  in  place  of 
cold  water.     Add  boiling  water.     Note  the  effect. 


CARBOHYDRATE  IN  THE  FORM  OF  STARCH  23 

E3q)eriment  4.  Effect  of  Acid  on  Starch. — (a)  Add  lemon  juice 
to  a  starch  solution  and  continue  cooking.  Observe  the  effect  and 
explain.     Divide  the  result  in  two  portions. 

(b)  Test  result  of  (a)  with  iodine. 

(c)  Test  result  of  (a)  with  Fehling's  solution. 
Explain. 

Experiment  5.  Experiment  Showing  Starch  Digestion. — Collect 
and  filter  a  small  amount  of  saliva.  Add  it  to  starch  paste  in  a  test 
tube.  Keep  the  tube  in  a  water  bath  not  above  98°  F.  for  fifteen 
minutes. 

Test  one-half  the  amount  with  iodine. 

Test  one-half  the  amount  with  Fehling's  solution. 

Explain  the  results  of  the  tests. 

SUGGESTIONS  FOR  LABORATORY  PRACTICE 

In  connection  with  the  study  of  the  text  of  the  preceding  chapter: 
Make  a  mould  of  corn  starch  pudding. 
Make  a  cup  of  medium  white  sauce. 


CHAPTER  V 
CEREAL  FOODS 

45.  Cereals. — The  cereals,  so  named,  from  Ceres,  god- 
dess of  grain  and  the  harvest,  include  the  grains  or  cultivated 
grasses  whose  seeds  are  used  for  food.  The  cereals  most 
Used  in  the  various  preparations  known  as  breakfast  foods 
are  wheat,  oats,  and  Indian  corn  or  maize. 

Rice,  rye,  barley  and  buckwheat  belong  to  the  cereals, 
but  they  are  not  commonly  made  into  mush  or  porridge 
to  be  served  as  a  breakfast  dish. 

46.  Wheat. — Wheat  is  the  typical  bread-making  grain, 
although  innumerable  preparations  of  wheat  in  the  form 
of  breakfast  foods  are  to  be  found  on  the  market.  Of  these 
Farina,  Wheatena,  and  Cream  of  Wheat,  in  which  the  wheat 
kernels  are  finely  ground,  are  very  generally  used.  Cracked 
Wheat,  Pettijohn,  Shredded  Wheat,  and  Puffed  Wheats  are  all 
well-known  preparations. 

47.  Oats. — From  Table  III,  in  which  is  given  the  com- 
position of  cereals,  it  will  be  seen  that  oats  are  rich  in  pro- 
tein, fat,  and  mineral  matter.  They  contain  also  a  good 
percentage  of  carbohydrate.  Oats  are  probably  the  most 
nutritious  of  all  the  cereals 

In  the  preparation  of  whole  oats,  or  Scotch  oats,  the 
grains  are  first  scoured  and  the  husk  removed.  For  the 
rolled  oat  products,  the  form  in  which  oats  are  most  com- 
monly used  as  breakfast  food,  the  grains  are  rolled  instead 
of  being  crushed  or  ground,  that  is,  they  are  subjected  to 
great  pressure  which  breaks  down  the  cellulose  and  flattens 
the  grains  so  that  they  are  easily  softened  by  the  cooking 
process.    By  the  application   of  heat   during  the   rolling 

24 


CEREAL  FOODS 


25 


RICE  RYE  BARLEY 

Fig.  3. — Heads  of  the  common  grains. 


26  FOOD 

process,  the  grains  are  partially  cooked,  though  not  to  the 
extent  claimed  upon  most  packages. 

This  application  of  heat  is  also  said  to  act  upon  the  fats 
present  in  such  a  manner  as  to  preserve  their  natural  flavor 
and  to  prevent  them  from  becoming  rancid  when  they 
stand. 

48.  Indian  Corn  or  Maize. — Corn  is  a  native  American 
plant,  and  is  important  as  a  crop  in  this  country  because 
of  its  value  as  food  for  man  and  for  fattening  animals. 

Corn  is  used  for  food  chiefly  in  the  form  of  meal,  from 
which  mush  and  many  varieties  of  hot  breads  are  made. 
Meal  is  the  name  given  to  the  product  made  by  grinding  a 
whole  grain  without  separating  or  bolting  to  remove  the 
outside  or  bran  coats.  Yellow  corn  meal  and  white  corn 
meal  have  practically  the  same  food  value,  and  may  be  used 
interchangeably  in  preparing  corn  dishes. 

Hominy,  samp,  and  hulled  corn,  are  other  preparations 
of  corn  in  which  the  kernels  are  broken  to  varying  degrees 
of  fineness.  Hominy  is  popular  as  a  breakfast  food,  while 
samp  and  hulled  corn  are  gaining  in  favor  as  a  dinner  dish 
in  place  of  potatoes  or  other  starchy  foods. 

Commercial  starch  and  corn  syrup,  or  commercial  glu- 
cose, are  made  from  corn. 

49.  Rice. — While  rice  is  the  poorest  of  all  the  cereals  in 
protein  and  fat  content,  it  has  the  highest  percentage  of 
starch.  This  starch  is  found  in  small  and  easily  digested 
granules,  which  give  to  rice  a  special  dietetic  value  in  cer- 
tain diseases.  Rice  is  eaten  whole  with  cream  or  milk  or 
in  soups.  The  polishing  of  rice,  by  which  a  part  of  the 
outer  coat  is  removed,  improves  its  appearance  and  increases 
its  selling  quality,  but  decreases  its  nutritive  value.  About 
one-half  of  the  mineral  matter,  which  is  chiefly  in  the  form 
of  phosphates,  is  lost  in  the  polishing  process.  This  mineral 
matter  is  of  great  importance  in  the  maintenance  of  health. 
People  are  coming  to  realize  this  fact  and  to  demand  of 
the  dealers  the  brown  or  unpolished  rice. 


CEREAL  FOODS 


27 


Fig.  4. — Corn. 
(From  McCall's  "'"Studies  of  Crops.") 


28 


FOOD 


50.  Buckwheat. — Although  buckwheat  is  not  a  cereal 
in  the  sense  of  belonging  to  the  grasses,  it  is  sometimes 
grouped  with  the  cereals  as  a  matter  of  convenience.  From 
this  grain  is  made  the  flour  which  is  used  for  buckwheat 
cakes.  It  also  forms  a  poultry  food  highly  prized  by  poultry- 
men,  as  it  is  popularly  thought  to  increase  the  laying  capacity 
of  the  hens. 

51.  Barley. — The  chief  characteristic  of  barley  is  its 
richness  in  mineral  matter.  Barley  is  sold  as  pearl  barley, 
which  is  the  whole  kernel  after  the  hull  has  been  removed 
by  machinery,  and  in  the  form  of  a  meal  used  in  preparing 
barley  water  and  barley  gruel.  The  meal  is  also  mixed  with 
other  meals  in  the  making  of  a  black  bread  extensively 
used  in  some  countries. 

In  this  country  barley  is  used  largely  in  the  production 
of  malt. 

52.  Rye. — Because  of  the  amount  and  quality  of  the 
gluten  it  contains,  rye  flour  can  be  made  into  bread.  This 
is  practically  the  only  use  made  of  this  grain  in  the  United 
States. 

It  should  be  noted  that,  of  all  grains,  wheat  and  rye 
are  the  only  ones  that  contain  gluten  in  the  proper  pro- 
portion to  make  bread  of  a  hght  and  porous  texture. 

TABLE  III.— PERCENTAGE  OF  FOODSTUFFS  IN  DIFFERENT 

CEREALS 


Cereal. 


Wheat 

Rye 

Rice  (polished).. 
Rice  (in  husks). . 

Oats 

Maize 

Barley 

Buckwheat 


Protein. 

Carbo- 
hydrate. 

Fat. 

Mineral 
Matter. 

Water. 

11.0 

71.2 

1.7 

1.9 

12.0 

10.2 

72.3 

2.3 

2.1 

11.0 

6.9 

79.4 

0.4 

.5 

12.4 

6.8 

68.1 

1.6 

4.0 

10.5 

13.0 

68.6 

8.1 

2.1 

6.9 

9.7 

68.9 

5.4 

1.5 

12.5 

10.1 

69.5 

1.9 

2.4 

12.3 

10.2 

64.3 

2.2 

2.2 

13.0 

Cellu- 
lose. 


2.2 
2.1 
.4 
9.0 
1.3 
2.0 
[1.8 
Ll.l 


CEREAL  FOODS  29 

53.  Digestibility  of  Cereals. — The  digestibility  of  all 
cereal  products  depends  largely  upon  the  thoroughness 
with  which  they  are  cooked.  It  is  desirable  that  the  cell 
walls  of  the  starch  grains  be  softened  and  ruptured  by 
thorough  cooking  to  prepare  them  for  the  action  of  the 
digestive  fluids.  It  has  been  demonstrated  that  cooked 
starch  is  more  easily  and  quickly  changed  to  maltose  than 
raw  starch. 

As  a  group,  the  nutrients  of  the  cereals  are  readily 
absorbed  and  assimilated.  Cereals  rank  next  to  the  animal 
foods  in  this  respect.  The  cellulose,  which  is  not  itself 
digested,  furnishes  bulk  to  the  food  to  excite  the  peristaltic 
motion  of  the  stomach  and  hasten  the  digestive  process. 

Thorough  mastication  is  essential  with  starchy  foods, 
since  it  not  only  divides  the  food  into  smaller  particles  but 
also  insures  a  thorough  mixing  with  the  saliva,  thus  making 
possible  the  action  of  the  ptyalin  on  the  starch. 

Fruits  eaten  with  cereals  are  valuable  aids  to  digestion, 
as  the  added  flavor  and  increased  attractiveness  of  the 
dish  stimulates  the  glands  to  an  increased  flow  of  digestive 
juices. 

Numerous  uncooked  cereal  preparations  are  offered  for 
sale.  These  have  the  advantage  of  being  ready  for  immedi- 
ate use,  thereby  saving  time,  labor,  and  fuel,  but  undoubtedly 
have  a  questionable  nutritive  value,  as  compared  with  the 
cooked  whole  grains. 

54.  The  Use  of  Sealed  Packages. — Package  cereal  foods, 
although  more  expensive  than  the  same  weight  sold  in 
bulk,  are  usually  to  be  preferred  on  account  of  the  possibility 
of  greater  cleanliness  which  they  offer.  The  packages  are 
sealed  to  protect  the  contents  from  dust,  dirt  and  germs, 
and  the  additional  few  cents  per  pound  in  cost  is  a  wise 
expenditure  of  money.  So  much  stress  has  been  placed 
upon  this  precaution  of  recent  years  that  it  is  now  almost 
impossible  to  obtain  cereals  in  bulk. 

55.  Cooking   Cereals. — The   chief   purposes   in   cooking 


30  FOOD 

cereals  are  to  sterilize  them,  to  improve  their  flavor  and 
appearance,  and  to  make  them  more  digestible  by  breaking 
down  the  cell  walls,  thus  enabling  the  digestive  juices  to 
reach  the  nutrients. 

Since  it  has  been  found  that  starch  grains  are  not 
ruptured  by  heat  below  that  of  the  boiling-point  of  water, 
it  is  important  that  the  first  part  of  the  cooking  process 
should  take  place  at  that  temperature.  This  may  be  accom- 
plished by  placing  the  vessel  containing  the  cereal  directly 
over  the  fire  for  the  first  five  or  ten  minutes,  after  which 
the  cereal  may  be  allowed  to  steam  until  completely  cooked. 
The  time  required  for  cooking  varies  with  the  kind  of  grain 
and  the  method  of  preparation.  In  general,  the  finely 
ground  or  rolled  products  require  less  time  than  the  whole 
grains. 

The  theory  that  long  exposure  to  a  high  temperature 
is  harmful  to  the  growth-producing  element  found  in  the 
whole  grain  should  be  considered,  and  excessive  heating 
should  be  guarded  against. 

Before  cereals  are  ready  for  eating,  a  sufficient  amount 
of  water  must  be  added  to  swell  the  starch  grains  and  form 
a  mixture  of  the  proper  consistency.  As  a  rule  the  coarse- 
rolled  grains  require  twice  as  much  liquid  as  there  is  cereal, 
and  the  finely  ground  wheat  or  corn  products  about  four 
times  as  much. 

Table  IV  shows  the  proportions  of  cereal  and  water,  and 
time  of  cooking  for  the  different  cereal  foods. 

56.  Fruits  and  other  Accompaniments  to  Cereals. — 
Since  the  cereal  foods  are  largely  carbohydrate,  the  addi- 
tion of  fruits,  fresh  or  stewed,  increases  their  nutritive 
value  by  adding  mineral  salts  and  other  nutrients,  as  well 
as  their  palatability  by  supplying  flavor  and  variety.  Dates, 
figs,  or  raisins,  moulded  with  the  cereal  and  served  with 
cream,  make  a  pleasing  and  satisfying  luncheon  dish  for 
children.  Fresh  fruits,  such  as  berries,  bananas,  and  ripe 
peaches,  are  a  suitable  addition  to  the  uncooked  and  to 


CEREAL  FOODS 


31 


TABLE  IV.— PROPORTIONS  AND  TIME  OF  COOKING  FOR 
THE  COMMON  CEREALS 


Kind. 


Amt.  Cereal, 
Cups. 


Water, 
Cups. 


Time, 
Hours. 


Rolled  oats 

H.O 

Quaker  oats .... 

Whole  oats 

Petti  John 

Whole  wheat. .  .  . 
Cream  of  vvhecit. 

Wheatena 

Corn  meal 

Hominy 

Rice  (steamed) . . 
Rice  (boiled). .  .  . 
Barley  (steamed) 


4 

6-8 

2 

1 

4 

6-8 

4 

1 

31 

3 

4 

1 

21 

2 

8-12 

20min 

3 

2 

many  of  the  cooked  cereals.  The  acid  and  mineral  substances 
which  they  contain  are  desirable  adjuncts  to  starchy 
foods. 

Starch,  as  has  been  stated,  is  converted  into  sugar  in  the 
digestive  process,  therefore  sugar  is  an  unnecessary  addition 
to  breakfast  foods  except  to  give  flavor.  If  used  at  all,  it 
should  be  used  sparingly.  Milk  and  cream,  however,  sup- 
ply the  protein  and  the  fat  in  which  cereals  are  more  or  less 
deficient,  and  in  addition  furnish  the  growth-stimulating 
principles  or  vitamines  which  milk  and  cream  are  known 
to  contain. 

57.  Macaroni,  Spaghetti  and  Noodles. — Macaroni,  spa-\ 
ghetti  and  kindred  substances  are  made  from  a  hard,  spring  | 
wheat  flour  which  is  rich  in  gluten.  Because  of  the  gluten, 
a  substance  is  produced  which  can  be  drawn  or  moulded 
into  various  different  forms  such  as  tubes,  shreds,  letters, 
etc.  Water  is  added  to  the  flour  to  make  a  paste  of  the 
proper  consistency,  which,  when  formed  as  desired,  is 
thoroughly  dried.     All  of  these  products  absorb  about  three 


32  FOOD 

times  their  weight  of  water  in  cooking  and  increase  in  bulk 
to  a  corresponding  degree. 

Domestic  macaroni  and  similar  products  manufactured 
in  factories  in  this  country  are  to  be  preferred  to  the  home- 
made products  of  uncertain  cleanliness.  Good  macaroni 
may  be  judged  by  its  deep  cream  color  and  rough  texture. 
The  best  macaroni  breaks  without  spUtting  and  keeps  its 
shape  after  cooking. 

By  the  addition  of  cheese  or  various  other  sauces  to 
macaroni  or  spaghetti,  a  simple  and  satisfying  meat  sub- 
stitute may  be  made. 

Noodles,  made  from  flour,  salt,  and  egg,  in  a  variety  of 
forms,  are  added  to  soup  stock  to  make  noodle  soup  or 
may  be  served  in  place  of  a  vegetable  with  the  meat 
course. 

58.  Use  of  the  Double  Boiler. — A  double  boiler,  or  its 
equivalent,  a  small  sauce  pan  placed  in  a  larger  pan  of  water, 
is  commonly  used  in  cooking  cereals.  When  the  cereal 
has  been  started  in  the  inner  boiler  directly  over  the  fire, 
the  parts  of  the  boiler  are  placed  together  and  the  cooking 
completed  by  the  dry-steaming  method.  The  double  boiler 
does  away  with  the  necessity  for  stirring  and  watching  to 
keep  the  food  from  burning.  The  only  care  required  is  to 
keep  the  lower  part  of  the  boiler  or  the  larger  saucepan 
one-third,  or  thereabouts,  full  of  water.  The  food  in  the 
inner  boiler  never  reaches  the  boiling-point,  therefore  a 
much  longer  time  is  required  for  thorough  cooking. 

59.  The  Fireless  Cooker. — In  Fig.  5,  are  shown  the 
essential  parts  of  a  fireless  cooker.  The  food  to  be  cooked 
is  first  placed  in  one  of  the  covered  metal  containers  and 
heated  over  the  fire  to  the  boiling-point  or  cooked  for  a 
given  time  as  indicated  in  Table  V.  The  container  with 
its  contents  is  then  placed  in  the  food  chamber,  which  is 
surrounded  by  a  good  insulator  to  retain  the  heat  and 
utilize  it  for  cooking  the  food.  All  commercial  fireless 
cookers  are  equipped  with  one  or  more  hot  plates  or  radiators 


CEREAL  FOODS 


33 


for  use  in  baking  and  in  maintaining  a  cooking  temperature 
for  a  longer  period  of  time.  These  plates  are  first  heated 
over  the  fire  and  then  placed  in  the  cooking  chamber  under- 
neath or  above  the  food  container.  The  racks  upon  which 
these  plates  rest,  when  the  cooker  is  used  for  baking  pur- 
poses, surround  the  space  occupied  by  the  bread  or  cake. 


Fig.  5. — A  commercial  fireless  cooker. 


The  principle  upon  which  the  fireless  cooker  is  based 
may  be  applied  to  the  keeping  of  iced  or  frozen  mixtures 
at  a  low  temperature.  In  this  case  the  heat-insulating 
material  surrounding  the  food  chamber  prevents  the  entrance 
of  heat  from  without,  and  thus  maintains  the  low  tempera- 
ture of  the  food.     If  the  cooker  is  well  insulated,  a  food 


34 


FOOD 


may  be  cooking  in  one  compartment  while  a  mixture  is 
kept  chilled  in  another  compartment  of  the  same  cooker. 

60.  Selection  and  Care  of  Fireless  Cookers. — In  choos- 
ing a  fireless  cooker  the  attention  should  be  directed  to  the 
durability  of  the  different  parts.  The  outside  case  or  box 
may  be  of  finished  hard  wood  or  metal,  preferably  of  metal 
because  it  is  easier  to  keep  clean.  The  lining  of  this  box 
should  be  of  a  durable  material  and  at  the  same  time  one 
that  will  clean  easily.  The  food  chamber  should  have  a 
seamless  metal  lining  to  prevent  the  collection  of  germs. 
The  food  containers  should  also  be  free  from  seams  or 
corners  where  particles  of  food  might  find  a  hiding  place. 
Each  food  container  should  be  fitted  with  a  tight  cover 
held  in  place  by  fasteners.  The  hot  plates  are  best  when 
made  of  soapstone,  which  heats  slowly  but  retains  the  heat 
for  a  long  time.  The  racks  should  be  firm  and  strong  enough 
to  bear  the  weight  of  the  hot  plates. 

Various  non-metal  substances,  such  as  asbestos,  excelsior, 
or  paper,  are  used  for  insulating  the  different  cookers.  The 
more  perfect  the  insulation  the  better  the  results.  A 
vacuum,  the  insulator  employed  in  the  construction  of  some 
of  the  more  expensive  cookers,  is  the  most  effective  means 
of  maintaining  a  constant  temperature. 

61.  A  Home-made  Fireless  Cooker. 
— An  improvised  cooker  that  will  serve 
the  designed  purpose  in  a  satisfactory 
manner  may  be  constructed  at  a  very 
slight  cost.  Such  a  one  is  shown  in 
Fig.  6.  A  box,  lard  pail,  candy  pail,  or 
other  container  having  a  tightly  fitting 
cover;  an  agate,  tin,  or  aluminum  cook- 
ing utensil,  also  having  a  close  fitting 
cover;  and  asbestos,  hay,  cork,  paper, 
or  excelsior  for  packing  purposes,  are 
the  essential  things. 

To  make  the  cooker  select  a  box  or  other  container  of 


Fig.  6. — A  home-made 
fireless  cooker. 


CEREAL  FOODS  35 

suitable  size,  having  the  required  tight  cover,  and  line 
it  throughout  with  asbestos  or  paper.  Choose  an  inner 
food  container,  having  a  tight  cover,  of  suitable  size  to  allow 
for  a  three-inch  space  between  it  and  the  outer  box  or  pail, 
and  cover  with  asbestos  or  stout  paper.  Pack  the  bottom 
of  the  box  three  or  more  inches  deep  with  one  of  the  above- 
mentioned  insulating  materials.  Put  the  covered  container 
in  place  on  the  bottom  pad  and  pack  the  space  around  it 
with  more  of  the  insulating  material,  filling  the  space  within 
three  inches  of  the  top  of  the  box. 

Make  a  pad  of  muslin  filled  with  the  insulating  material, 
that  will  exactly  fit  and  fill  the  box.  Close  the  fitted  cover 
tightly  when  in  use.  The  insulating  packing  material 
should  be  changed  frequently  to  keep  the  cooker  clean  and 
free  from  odors. 

62.  The  Use  of  the  Fireless  Cooker. — Cereals  are 
probably  the  food  suited  above  all  others  to  cooking  in  the 
fireless  cooker.  Dried  beans,  peas  and  lentils,  which  have 
a  high  starch  content  linked  with  protein  and  require  long 
cooking,  are  palatably  and  economically  prepared  in  the 
fireless  cooker. 

Tough  cuts  of  meat,  such  as  are  used  in  preparing  soup 
stock  and  stews,  and  especially  tough  fowls  are  successfully 
cooked  in  a  fireless  cooker.  Corned  beef,  hams,  tongues, 
and  other  cured  or  salted  meats  shrink  less  when  cooked  in 
this  way.  In  fact  the  cooker  is  admirably  suited  to  all  foods 
requiring  a  long,  slow  cooking  to  make  them  palatable  and 
digestible. 

It  is,  however,  of  extreme  importance  that  the  foods  thus 
cooked  be  reheated  before  serving,  to  remove  any  gases 
that  may  have  been  formed  in  the  slow-cooking  process. 

The  fireless  cooker  is  recommended  highly  for  use  in 
canning  small  fruits  such  as  cherries  and  all  kinds  of 
berries.  The  bright  color  is  preserved  and  the  appearance 
of  the  canned  goods  much  improved  by  this  method  of 
canning. 


36 


FOOD 


A  more  extended  use  of  the  fireless  cooker  is  recom- 
mended for  housekeepers  who  are  obHged  to  be  away 
from  home  the  greater  part'  of  the  day.  The  saving  in 
both  time  and  fuel  will  overbalance  the  initial  cost  of  the 
cooker. 


TABLE  5.— TABLE  FOR  COOKING  SOME  COMMON  FOODS 
IN  THE  FIRELESS  COOKER.      (Mitchell) 


Food. 


Amount. 


Amount 
of  Water, 


Amount 
of  Salt. 


Time  on 
Stove  in 
Minutes. 


Time  in 

Cooker  in 

Hours. 


Rolled  oats 

Corn  meal  mush. 

Hominy. .  : 

Rice 


Soup  stock . 


Stew. 


Corned  beef . 


Tongue , 


Ham. 


Ic. 
Ic. 
1  c. 
Ic. 


2  lbs. 
meat 

lib. 

meat 

8  lbs. 


Dried  beans,  peas,  or 
lentils 


Ic. 


2|  c. 
4|c. 
5  c. 
2ic. 


2  qts. 


2ic. 


Water 

to 
cover 
Water 

to 

cover 

Water 

to  cover 

3  qts. 


1  tsp. 
1  tsp. 
U  tsp. 
1  tsp. 


1  tbs. 


1  tsp. 


To  taste 


5 
5 

10 
Bring  to 
boiling 
point. 
10 
simmer- 
ing 
o 
simmer- 
ing 
Simmer, 
30-40 

Simmer 
20-30 

Simmer 
20-30 

Boiling- 
point 


2-12 

5-10 

10-12 

1 


9-12 

4-6 

10-12 

10-12 

7-10 
8-10 


63.  The  Thermos  Bottle. — The  various  styles  of  thermos 
or  vacuum  bottles  now  in  use  depend  upon  the  vacuum 
surrounding  the  inner  bottle  to  act  as  insulator  to  maintain 
the  temperature  of  the  contents  of  the  bottle.  This  is  an 
application  of  the  same  principle  as  that  upon  which  the 
fireless  cooker  is  based. 


CEREAL  FOODS 


37 


In  Fig.  7,  is  shown  a  thermos  bottle  closed,  and  in 
Fig.  8,  the  construction  of  the  same.  The  glass  vessel 
in  Fig.  8  is  double ,  walled  with  a  vacuum  or  insulating 
space  between.  This  glass  vessel  is  set  upon  a  spring  in 
the  outer  container  which  prevents  breakage  in  handling. 
The  material  of  the  outer  container  may  be  of  tin,  agate, 


Courtesy  of  Landers,  Frary  &  Clark. 

Fig.  7. — Thermos  bottle 
closed. 


Courtesy  of  Landers,  Frary  &  Clark. 

Fig.  8. — Vacuum  bottle  showing  the 
various  parts. 

1  Vacuum  vessel  or  glass  filler; 

2  The  spring  steel  shock  absorber; 

3  Nickel-plated  brass  case  in  which  glass  filler 

is  placed,  resting  on  shock  absorber; 

4  Nickel-plated  shoulder  which  screws  to  case, 

holds  filler  in  place; 
6  Gasket  which  fits  to  neck  of  bottle  so  that  no 
liquid  can  enter  case; 

6  Cork  stopper; 

7  Nickel-plated  cap  or  drinking  cup  which  screws 

to  base. 


glass,  nickel,  silver,  etc.,  depending  upon  the  price  and  the 
use. 

The  convenience,  comfort  and  value  of  the  thermos 
bottle  for  the  school  lunch  box,  the  laborer's  lunch  box, 
picnic  parties,  and  long  motor  trips  cannot  be  overestimated. 
The  range  of  prices  brings  some  kind  of  a  vacuum  bottle 
within  the  reach  of  all. 


38 


FOOD 


64.  The  Pressure  Cooker. — A  steam  pressure  cooker, 
Fig.  9,  made  of  solid  aluminum  and  equipped  with  a  steam 

gauge  .which  registers  the 
amount  of  steam  pressure 
used,  is  to  be  had  in  sizes 
suitable  for  family  use.  Cook- 
ing food  under  steam  press- 
ure in  the  home  is  a  com- 
paratively new  idea  and  one 
that  is  not  yet  in  general  use. 
The  points  which  recommend 
the  pressure  cooker  to  the 
housekeeper  are  the  saving 
in  time,  labor  and  fuel. 
Foods  will  cook  in  one-half 
or  less  time  than  in  the  ordi- 
nary cooking  utensils.  The 
pressure  cooker  is  highly 
recommended  for  use  in  can- 
ning fruits  and  vegetables 
because  it  shortens  the  period 


Fig.  9. — Pressure  cooker. 


(Fanners'  Bulletin  839,  U.  S.  Dept.    ^f  sterilization. 

The  high  price  of  the 
pressure  cooker  as  now  made  places  it  beyond  the  reach  of 
the  average  household,  although  it  is  claimed  that  by  the 
saving  in  fuel  alone  it  will  pay  for  itself  in  a  short  time. 

SUGGESTIONS  FOR  LABORATORY  PRACTICE 

In  ronnection  with  the  study  of  the  text  of  the  preceding  chapter: 

Cook  oatmeal  in  a  fireless  cooker. 

Cook  rolled  oats  as  an  example  of  coarse  cereals. 

Cook  farina  as  an  example  of  fine  cereals. 

Boil  and  steam  rice. 

Cook  macaroni  or  spaghetti  and  serve  with  white  sauce. 


CHAPTER  VI 
FLOUR  MIXTURES 

65.  Definition. — Flour  mixtures  are  such  mixtures  as 
contain  flour  as  the  chief  ingredient.  The  essentials  in 
flour  mixtures  are  flour,  liquid,  salt,  and  some  kind  of  a 
leavening  agent.  The  additions,  or  non-essentials,  are  the 
ingredients  added  to  produce  an  agreeable  taste,  to  improve 
the  texture,  or  to  introduce  a  larger  proportion  of  nutrients. 
These  are  seasoning,  shortening,  fruit,  nuts,  and  flavorings. 

66.  Leavening  Agents. — To  leaven  means  "  to  make 
light."  It  is  necessary  to  introduce  some  kind  of  a  leaven- 
ing substance  into  a  flour  mixture  to  render  the  mixture 
light,  porous,  and  digestible.  A  leavening  agent  as  used  in 
cookery  is  a  substance  which  contains  a  gas,  or  which  has 
the  power  to  produce  a  gas.  The  expansion  of  this  gas 
during  the  process  of  baking  causes  the  mixture  to  rise. 

The  leavens  are  air,  steam,  and  gas,  produced  by  the 
action  of  some  kind  of  a  leavening  agent  incorporated  in  the 
mixture. 

Air  is  the  simplest  of  the  leavens.  By  beating,  folding 
or  rolling  a  mixture,  a  sufficient  volume  of  air  is  often  intro- 
duced to  cause  the  mixture  to  rise  satisfactorily.  Examples 
of  such  mixtures  are  sponge  cake,  pie  crust,  and  beaten 
biscuit. 

The  steam  produced  from  the  liquid  added  to  a  mixture, 
together  with  the  air  incorporated  by  beating  or  other 
manipulation,  forms  the  leaven  in  such  mixtures  as  pop-over 
batter. 

Gas  produced  by  chemical  agents  introduced  into  the 
mixture  for  this  purpose,  such  as  baking  powder  and  bicar- 
bonate of  soda,  is  the  ordinary  leavening  agent  made  use 

39 


40  FOOD 

of  when  time  cannot  be  allowed  for  the  longer  process  of 
fermentation.  Examples  are  quick  bread  and  cake  mixtures. 
A  second  way  in  which  gas  for  leavening  may  be  pro- 
duced within  the  mixture  is  by  the  use  of  yeast.  The  yeast 
causes  alcoholic  fermentation  of  the  sugar  present,  setting 
free  the  gas,  carbon  dioxide  (CO2).  This  is  the  purpose  of 
the  yeast  used  in  bread  making. 

67.  Baking  Powders. — Three  different  kinds  of  baking 
powder  are  in  general  use.  All  of  thes.  contain  bicarbonate 
of  soda  as  a  source  of  carbon  dioxide  (CO2)  and  require  an 
acid  reagent  capable  of  liberating  this  gas. 

Tartrate  powders  are  those  in  which  tartaric  acid  or 
its  salt,  cream  of  tartar,  is  employed  as  this  acid  reagent. 

Phosphate  powders  are  those  made  with  calcium  or 
sodium  phosphate  as  the  acid  reagent.  Crystallized  mono- 
sodium  phosphate  as  produced  by  a  recently  demonstrated 
chemical  process  is  the  phosphate  used  in  the  best  of  this 
class  of  powders. 

Alum  powders  are  those  in  which  the  ammonium  and 
sodium  alums  are  used  to  release  the  gas. 

In  addition  to  the  above  chemicals  a  small  amount, 
about  20  per  cent,  of  corn  starch  or  some  other  substance  is 
used  to  prevent  the  gathering  of  moisture  which  will  cause 
deterioration  of  the  powder. 

There  is  also  in  each  case  a  small  amount  of  residue 
or  by-product  resulting  from  the  action  of  the  ingredients 
in  the  powder.  It  is  a  question  whether  this  by-product  is, 
in  any  case,  as  harmful  as  was  formerly  believed.  Dis- 
cussions of  the  relative  merits  of  the  different  powders 
savor  so  much  of  commercialism  that  it  is  hard  to  find 
unprejudiced  information  on  this  point.  It  is  safe  to  say 
that  in  the  small  amounts  in  which  baking  powders  are 
ordinarily  used,  the  deleterious  effects  from  the  by-products 
are  negligible. 

68.  Analysis  of  a  Cream  of  Tartar  Baking  Powder. — 
Cream  of  tartar  baking  powder  is  composed  of  two  parts 


FLOUR  MIXTURES  41 

by  weight  of  acid  potassium  tartrate,  or  cream  of  tartar, 
to  one  part  of  bicarbonate  of  soda,  with  an  addition  of 
twenty  per  cent  of  starch  as  a  filler.  When  this  compound 
comes  in  contact  with  the  liquor  in  a  batter  or  a  dough, 
the  two  soluble  ingredients  gradually  dissolve.  In  solution 
a  chemical  change  takes  place  and  new  compounds,  carbon 
dioxide  and  sodium-potassium  tartrate,  commonly  known 
as  Rochelle  Salts,  are  formed,  as  is  shown  by  the  following 
reactions: 

Acid  potassium  tartrate.        Bicarbonate  soda.  Sodium-potassium  tartrate. 

HKC4H4O6     +     NaHCOs  =   NaKC4H406+C02+H20 

69.  Source  of  Cream  of  Tartar. — Cream  of  tartar, 
together  with  other  salts  and  some  coloring  matter,  is 
found  as  a  deposit  in  the  form  of  crystals  called  argols  on 
the  sides  of  wine  vats.  These  argols  are  melted  and  filtered 
through  bone  black  to  remove  the  color  and  other  impurities. 
The  resulting  liquid  is  then  recrystallized  as  pure  cream 
of  tartar.  These  crystals  are  ground  to  an  extremely  fine 
powder  before  combining  with  soda  to  form  baking  powder. 

70.  Source  of  Bicarbonate  of  Soda. — Although  there 
are  other  ways  of  making  bicarbonate  of  soda  or  baking 
soda,  the  ammonia  or  Solvay  process,  with  reactions  as  shown 
below,  is  still  used.  Equation  (1)  shows  the  chief  reaction, 
while  equation  (2)  shows  the  recovery  of  the  ammonia, 
which  is  the  key  to  the  commercial  success  of  this  process. 

(1)  NaCH-NH4+H20+C02  =  NH4CH-NaHC03. 

(2)  2NH4C14-Ca(OH)2  =  CaCl2+H204-2NH4. 

71.  Action  of  Soda  with  Sour  Milk,  Molasses  and 
Chocolate. — Sour  milk  contains  an  acid  (lactic)  which  acts 
chemically  upon  bicarbonate  of  soda,  setting  free  the  CO2. 
Sour  milk  and  soda  may  be  substituted  for  sweet  milk  and 
baking  powder  in  making  many  of  the  quick  breads  and 
cakes.  The  chief  difficulty  for  the  beginner  is  to  determine 
the  degree  of  acidity  of  the  milk  and  to  know  how  much 


42  FOOD 

soda  "is  required.  Ordinarily  one-half  teaspoonful  of  soda 
will  be  sufficient  for  one  cup  of  sour  milk  or  buttermilk. 

In  using  molasses  the  free  acid  present  will  be  neutralized 
by  the  addition  of  one-half  teaspoonful  of  soda  for  each 
cupful  of  molasses. 

Soda  has  the  power  to  darken  the  chocolate  in  a  mixture 
and  to  neutralize  the  free  fatty  acids  present  in  the  chocolate 
and  release  the  gas. 

72.  Home-made  Baking  Powder. — Many  housekeepers 
prefer  to  use  cream  of  tartar  and  baking  soda  as  a  substitute 
for  baking  powder.  When  so  used,  a  scant  teaspoonful 
of  soda  mixed  with  two  teaspoonfuls  of  cream  of  tartar  is 
an  equivalent  for  three  teaspoonfuls  of  baking  powder. 
It  is  best  to  prepare  a  small  quantity  of  the  mixture  in  the 
proper  proportion  and  have  it  ready  for  use  as  required. 
The  materials  should  be  weighed  accurately  and  mixed 
thoroughly  by  sifting  several  times  after  combining.  This 
mixture  should  be  kept  tightly  covered  in  a  glass  jar. 

73.  Classification  of  Flour  Mixtures. — According  to  kind: 

.  .  ,  f  Hot  or  quick  breads 

^  ^  \  Yeast  breads 

r  Pies 
(3)  Pastry  Tarts 

i  Patties 

According  to  thickness: 

Pour 


(1)  Batters  |  ^^^^ 

Soft 


(2)  Doughs  I  g^.^ 

A  hatter  is  a  mixture  of  some  starchy  substance,  as 
flour  or  meal,  and  a  liquid,  in  proportions  to  form  a  com- 
bination that  can  be  beaten  with  a  spoon. 


FLOUR  MIXTURES 


43 


I         I 


\^ 


%. 


Courtesy  oj  Royal  Baking  Powdtr  Co. 

Fig.  10.— Waffles. 


Courtesy  of  Royal  Baking  Powder  Co, 
Fig.  11.— Muffins. 


44  FOOD 

A  dough  is  a  flour  mixture  stiff  enpugh  to  be  kneaded  on 
a  board. 

Pour-batter  is  the  thinnest  of  the  flour  mixtures,  and 
contains  about  an  equal  amount  of  flour  and  liquid.  A 
definite  proportion  cannot  always  be  maintained,  since  there 
is  a  variation  in  the  thickening  power  of  the  different  flours, 
as  well  as  in  the  wetting  capacity  of  the  different  liquid 
ingredients.  Griddle  cake  mixture  and  pop-over  batter 
are  excellent  examples  of  this  class  of  flour  mixtures. 

Drop-hatter  is  a  mixture  containing  approximately  two 
parts  of  flour  to  one  part  of  liquid.  A  good  example  is 
muffin  batter.  In  this  case  as  in  the  case  of  the  pour- 
batters,  the  proportion  of  the  essential  ingredients  will 
depend  upon  the  kind  of  flour  used  and  upon  the  properties 
of  the  other  ingredients. 

Soft-dough  contains  from  two  and  one-half  to  three 
parts  of  flour  to  one  part  of  liquid.  Biscuit  dough  is  typical 
of  this  class. 
7  Stiff-dou^h  has  the  proportion  of  flour  and  liquid  of 
four  to  one.  Pie  crust  is  the  best  example  of  this  class  of 
doughs. 
^  74.  Hot  or  Quick  Breads. — As  the  name  indicates,  hot 
or  quick  breads  are  prepared  in  a  much  shorter  time  than 
that  necessarily  taken  for  yeast  breads  which  are  discussed 
in  the  succeeding  chapter.  Some  chemical  means  of  pro- 
ducing CO2  is  depended  upon  to  give  the  necessary  lightness 
to  this  class  of  breads. 

75.  Cakes. — The  cake  mixtures  are  divided  into  two 
classes,  sponge  and  butter.  The  first  class  comprises  all 
varieties  of  cake  batter  not  containing  shortening  of  any 
kind  and  depending  upon  air  for  leavening.  The  second 
class  includes  all  forms  of  cake  batter  which  contain  butter 
or  other  fats  and  depend  upon  the  gas  released  from  soda, 
as  in  baking  powder,  or  the  use  of  baking  soda  and  some 
acid  substance,  for  leavening. 

76.  Sponge   Cake. — This  is  the  simplest  of  the  cake 


FLOUR  MIXTURES 


45 


Courtesy  oj  Royal  Baking  Powder  Co. 

Fig.  12. — Cinnamon  Buns. 


Courtesy  of  Royal  Baking  Powder  Co. 

Fig.  13.— Corn  Cake. 


46 


FOOD 


mixtures  in  respect  to  the  number  of  ingredients,  but  it 
is  the  most  difficult  to  make  successfully.  Since  air  is 
depended  upon  for  leavening,  it  is  most  essential  that  the 
means  of  combining  the  few  ingredients  be  the  one  that 
will  imprison  the  greatest  amount  of  air.  The  white  of 
egg  will  hold  more  air  than  the  yolk,  therefore  the  parts  of 
the  egg  are  beaten  separately  and,  as  a  last  step,  the  stiffly 
beaten  white  is  carefully  folded  into  the  other  ingredients. 
More  air  may  be  incorporated  into  the  white  of  egg 
than  into  almost  any  other  substance,  because  of  the  albumin 
it   contains.     When   beaten   this   albumin   forms  the   wall 


Fig.  14.— Butter  Cake. 


inclosing  the  air  bubbles.  The  addition  of  acids,  such  as 
lemon  juice  or  cream  of  tartar,  toughens  this  thin  albumin- 
ous covering,  and  makes  it  possible  for  the  gas  to  expand 
without  rupturing  the  containing  wall,  thus  giving  the 
spongy  texture  from  which  the  cake  derives  its  name. 

77.  Butter  Cake. — Butter  cake  mixture  is  a  modified 
muffin  batter.  More  shortening,  sugar,  and  egg  is  used 
and  some  kind  of  flavoring  substance  is  added,  together 
with  the  special  ingredient  which  determines  the  particu- 
lar variety  of  cake;  e.g.  chocolate,  fruit,  nut,  etc. 

78.  Ingredients  and  Their  Effect  on  the  Mixture.* — For 

*  Suggested  by  Cornell  Bulletin  No.  73. 


FLOUR  MIXTURES  47 

satisfactory  results  in  cake  making,  it  is  most  essential 
that  all  the  ingredients  should  be  of  the  best  quality  in 
respect  to  flavor  and  freshness. 

Flour. — A  good,  standard  grade  of  flour  should  be  used. 
This  should  be  sifted  twice  before  measuring.  There  is 
less  variation  in  the  weight  of  different  flours  after  they 
are  sifted  twice,  and  more  uniform  results  may  be  obtained 
through  observing  this  precaution.  Flour  is  sifted  to 
remove  foreign  substances,  to  take  out  lumps,  and  to  incor- 
porate air.  The  amount  of  air  introduced  is  greatly  increased 
by  a  second  sifting.  Many  cake  rules  call  for  pastry  flour 
but  when  this  is  not  obtainable,  bread  flour  may  be  sub- 
stituted, using  two  tablespoonfuls  less  for  each  cupful  of 
flour  than  the  rule  specifies.  It  has  been  demonstrated 
that  two  tablespoonfuls  of  cornstarch  added  to  each  cup 
of  bread  flour  makes  an  excellent  substitute  for  pastry 
flour. 

Too  much  flour  in  a  cake  will  cause  it  to  become  tough 
and  bread-like.  On  the  other  hand,  if  not  enough  flour 
is  used,  the  cake  will  fall  because  there  is  not  enough  gluten 
in  the  rhixture  to  stiffen  on  baking  and  hold  the  cake  up. 
The  starch  in  the  flour  binds  the  other  ingredients  together 
and  gives  body  to  the  cake. 

Sugar.^A  fine-grained,  granulated  sugar  should  be 
sought  for  cake  making,  since  it  dissolves  more  readily  than 
the  coarse  grained  and  makes  a  cake  of  finer  texture.  When 
powdered  or  brown  sugar  is  used  in  place  of  granulated,  it 
is  advisable  to  make  the  substitution  by  weight  rather 
than  by  measure,  as  from  one  and  a  quater  to  one  and  a  half 
cupfuls  are  required  to  furnish  an  equivalent  sweetening 
to  one  cupful  of  granulated  sugar.  Since  sugar  dissolves 
and  increases  the  moisture  in  a  cake,  too  much  tends  to 
make  the  cake  rise  high  in  the  oven  and  then  fall  before 
the  baking  process  is  finished.  In  this  case  the  crumb 
will  be  sticky  and  the  crust  gummy.  Too  little  rugar 
produces  a  coarse-grained  cake. 


48  FOOD 

Butter  or  Other  Fats. — Butter  used  for  cake  making 
should  not  have  an  objectionable  flavor  or  odor,  as  both  of 
these  may  be  detected  in  the  cake  when  baked.  Butter  has 
the  effect  of  making  a  cake  rich,  tender,  and  of  fine  texture, 
but  a  definite  proportion  (1:4)  between  butter  and  flour 
should  be  maintained  for  the  best  results. 

Cheaper  fats  may  be  substituted  for  butter  fat  for  use 
in  cake  making.  Of  these  fats,  fresh  lard,  chicken  fat,  and 
cottonseed  oil  are  most  frequently  used.  A  less  amount  of 
the  softer  fats  and  oils  is  needed  when  substituted  for  butter 
because  they  contain  less  moisture  and  are  free  from  curds, 
salt,  or  other  foreign  substances  and  have  a  correspondingly 
greater  shortening  power.  Seven-eighths  of  a  cupful  of  lard 
is  equivalent  to  one  cupful  of  butter. 

A  rich  cake,  one  that  contains  an  excess  of  fat,  will  be 
fine  grained,  crumbly,  and  hard  to  get  out  of  the  baking 
tin,  while  one  containing  a  small  amount  of  fat  will  be  light 
and  porous  but  will  dry  out  rapidly.  An  increase  of  fat 
in  a  recipe  calls  for  a  corresponding  increase  in  the  amount 
of  flour  and  egg  or  baking  powder. 

Eggs. — Eggs  impart  lightness  and  smoothness  of  texture 
to  a  cake  and  help  to  bind  the  ingredients  together.  They 
also  give  toughness,  especially  the  white.  Therefore, 
when  whites  are  used  in  place  of  yolks,  one  teaspoonful 
of  fat  should  be  added  for  each  additional  white  to  make  up 
for  the  fat  content  of  the  yolks  (J  of  which  is  said  to  be  fat). 
Because  of  this  fat,  which  will  not  allow  it  to  hold  air,  the 
egg  yolk  cannot  be  beaten  to  a  stiff  froth  like  the  white. 
This  is  demonstrated  when  a  little  of  the  yolk  is  left  in  the 
white  and  prevents  the  formation  of  a  stiff  froth  that  will 
keep  its  shape. 

Good  cold-storage  eggs,  or  eggs  preserved  by  some  of 
the  common  household  methods,  may  be  used  instead  of 
fresh  ones  when  the  price  of  strictly  fresh  eggs  is  prohibitive. 

It  is  possible  to  make  a  cake  light  and  at  the  same  time 
good-tasting  with  a  small  amount  of  egg  by  increasing  the 


FLOUR  MIXTURES  49 

quantity  of  baking  powder.  An  example  is  the  one-egg 
or  standard  cake,  which  is  good  when  eaten  soon  after 
making,  but  which  dries  out  quickly. 

Liquids. — Although  sweet  milk  is  the  liquid  generally 
called  for  in  cake  recipes,  other  liquids  are  often  used. 
Water,  which  toughens  the  cake  slightly,  is  probably  the 
chief  substitute  for  sweet  milk. 

Sour  Milk. — When  sour  milk  or  buttermilk  is  used  as 
the  liquid  in  a  cake  recipe,  bicarbonate  of  soda  (one-half 
teaspoonul  for  each  cupful  of  tnilk)  is  ordinarily  required 
to  neutralize  the  acid  before  adding  baking  powder. 

Sour  cream  takes  the  place  of  both  fat  and  liquid  in  a 
recipe.  One  cupful  of  sour  cream  is  regarded  as  equivalent 
to  one-third  to  one-half  cupful  of  shortening  and  two-thirds 
to  one-half  cupful  of  sour  milk. 

Fruits. — Fruits  are  added  to  cake  to  improve  the  flavor, 
to  add  weight  and  food  value  and  to  prevent  its  drying  out 
quickly.  Certain  dried  or  candied  fruits  such  as  currants, 
raisins,  citron,  cherries,  figs,  and  dates  are  used  in  cake 
making.  When  adding  dried  fruits,  the  batter  should  be 
slightly  stiff er  than  for  plain  cake,  in  order  to  hold  the  fruit 
in  place.  Also,  more  shortening  should  be  added  to  counter- 
act the  effect  of  the  extra  flour  used.  Raw  fruits,  such  as 
blue  berries  and  cherries,  require  a  smaller  amount  of  extra 
flour.  Cooked  fruits  apple  sauce,  blackberry,  and  other 
jams  require  very  little  additional  flour.  Dried  or  raw 
fruit  should  be  mixed  with  a  small  amount  of  flour  and 
added  to  the  mixture  just  before  baking. 

Nuts. — Nuts,  which  are  lighter  than  fruit,  do  not  need 
additional  flour  to  keep  them  from  settling  to  the  bottom  of 
the  tin.  They  add  such  richness  to  a  cake  mixture  that  one 
cup  of  nuts  is  equivalent  to  one  tablespoonful  of  fat. 

Chocolate  and  Cocoa. — Cocoa  may  be  used  in  any  recipe 
calling  for  chocolate  by  allowing  two  tablespoons  of  cocoa  to 
an  ounce,  or  a  square,  of  chocolate.  The  starch  found  in 
the  chocolate  or  cocoa  thickens  the  batter,  which  accounts 


50  FOOD 

for  the  fact  that  less  flour  or  more  liquid  is  called  for  when 
chocolate  or  cocoa  is  used.  The  fat  of  the  chocolate  or 
cocoa  adds  richness  to  the  cake  and  may  be  taken  into 
consideration  in  the  addition  of  other  fats. 

Spices  and  Flavoring  Extracts. — Spice  may  be  added  to 
a  cake  mixture  by  sifting  with  the  dry  ingredients  or  by 
first  scalding  with  about  twice  as  much  boiling  water  as 
spice,  and  adding  to  the  liquid  ingredients.  The  latter 
method  is  highly  recommended  because  it  improves  the 
flavor  of  the  spice  and  imparts  a  richness  to  the  cake. 

Strong  vanilla,  lemon,  almond,  or  other  extracts  are  not 
needed  in  a  cake  made  of  good  materials,  and  should  be 
used  only  in  quantities  sufl&cient  to  impart  a  delicate  flavor 
rather  than  as  a  disguise  to  the  objectionable  flavor  and 
odor  of  poor  materials. 

79.  Baking  Cake. — Experience  is  the  only  guide  to 
successful  baking  unless  a  reliable  oven  thermometer  is  used. 
More  cakes  have  been  spoiled  in  the  baking  than  by  faulty 
recipes  or  careless  mixing.  A  loaf  cake  should  be  baked  on 
the  bottom  shelf  of  the  oven  in  order  to  have  the  greater 
heat  underneath.  Cookies  and  small  cakes  are  baked  more 
evenly  on  the  upper  shelf. 

In  fining  the  pan  bring  the  batter  up  against  the  sides 
so  that  the  center  will  not  be  higher  than  the  sides,  and 
in  this  way  bring  a  larger  proportion  of  the  batter  in  con- 
tact with  the  heat  at  the  sides  of  the  pan.  This  makes  the 
cake  rise  evenly.  The  pan  should  not  be  more  than  two- 
thirds  full  of  batter,  or  the  cake  will  rise  over  the  sides  of  the 
pan  and  fall  later. 

An  over-hot  oven  does  not  allow  the  cake  to  rise  evenly 
and  an  oven  too  cool  allows  the  mixture  to  become  over- 
light,  thus  spoiling  the  texture  of  the  cake.  Since  the  range 
of  oven  temperature  runs  from  250°  F.  (cool)  to  500°  F.  (very 
hot),  some  reliable  means  is  necessary  to  accurately  measure 
the  heat  of  the  oven.  The  methods  of  testing  oven  tem- 
peratures most  commonly  employed  when  a  thermometer 


FLOUR  MIXTURES 


51 


is  not  used  are:  Testing  with  the  hand,  noting  how  quickly 
a  piece  of  paper  browns  in  the  oven,  and  allowing  a  stated 
time  after  the  gas  has  been  turned  on  before  putting  in  the 
cake.  Any  one  of  these  may  be  adequate  in  the  hands  of 
an  expert,  but  for  the  inexperienced  the  only  sure  method 
is  the  use  of  an  oven  thermometer. 

A  dish  of  cold  water  placed  on  the  upper  grate  will  lower 
the  temperature  of  the  oven.  Leaving  the  door  ajar  is  safe 
only  after  the  cake  is  partly  baked. 

TABLE  VL— OVEN   TEMPERATURES 

(From  Teachers'  College  Bulletin  No.  8) 


Cool. 

Moderate. 

Hot. 

Very  Hot. 

250-350°  F. 
Custards 
Meringues 
Sponge  cake 

350-400°  F. 
Ginger  bread 
Butter  cakes 
Cookies 
Bread 

400-450°  F. 

Rolls 

Pop-overs 

Biscuits 

Muffins 

450-500°  F. 
Pastry 

80.  Stages  in  Baking  a  Cake. — The  time  required  for 
baking  a  cake  may  be  divided  into  four  periods.  First,  the 
cake  rises  to  its  full  capacity.  Second,  a  crust  is  formed  on 
top  which  is  brown  in  spots.  Third,  the  cake  is  an  even 
golden  brown.  Fourth,  it  shrinks  from  the  sides  of  the  tin, 
becomes  elastic  to  the  touch  and  a  broom  splint  inserted 
will  come  out  clean. 

81.  Care  After  Baking. — After  a  cake  has  stood  in  the 
tin  long  enough  to  become  moist  around  the  sides,  it  should 
be  removed  from  the  tin  and  inverted  on  a  rack  to  cool. 
This  usually  takes  about  three  minutes.  Cakes  to  be  iced 
need  to  be  partly  cooled  before  the  icing  is  put  on  or  the 
heat  of  the  cake  will  cause  the  icing  to  run. 

82.  How  to  Know  a  Good  Cake. — A  properly  made  cake 
should  be  of  uniform  thickness,  fine  grained,  and  of  delicate 
texture.    Cake  that  rises  in  the  middle  or  at  the  sides  of  the 


52  FOOD 

tin,  either  has  too  much  flour  in  it  or  has  been  improperly 
baked.  A  coarse  grain  and  texture  indicate  careless  measur- 
ing or  insufficient  mixing.  A  good  cake  is  light,  tender, 
and  moist,  easily  broken,  but  not  crumbly.  The  crust 
should  be  thin,  tender,  and  evenly  browned. 

SUGGESTIONS  FOR  LABORATORY  PRACTICE 

In  connection  with  the  study  of  the  text  of  the  preceding  chapter: 
Make  pop-overs,  griddle  cakes,  waffles,  fritters,  muffins,  and  tea 
biscuit. 

Make  sponge  and  butter  cakes,  cookies,  and  gingerbread. 


CHAPTER  VII 

FLOUR  MIXTURES,  BREAD  AND  PASTRY 

{Continued) 


83.  Varieties  of  Wheat. — Spring  wheat  is  grown  in  the 
Northwestern  States  and  Canada.  It  is  sown  in  the  spring 
and  grows  and  matures  during  the  short,  hot,  summer 
months  and  is  harvested  in  the  early  fall.  Spring  wheat, 
because  it  is  rich  in  the  right  kind  of  proteins,  is  considered 
best  for  bread  flour. 

Spring  wheat  flour  is  known  by  its  creamy  white  color, 
its  gritty  feeling  when  rubbed  between  the  thumb  and 
finger,  and  its  power  to  absorb  water. 

Winter  wheat,  which  is  sown  in  the 
fall,  reaches  maturity  in  the  early  sum- 
mer. The  kernels  of  winter  wheat  are 
softer  and  contain  more  starch  than 
those  of  spring  wheat,  and  for  this 
reason  winter  wheat  is  used  for  making 
pastry  flour.  This  flour  is  whiter  in 
color  than  bread  flour.  It  has  a  smooth, 
starchy  feeling  and  holds  its  shape  when 
squeezed  in  the  hand. 

84.  Structure  and  Composition  of  a 
Wheat  Kernel. — The  structure  of  a 
wheat  kernel  is  shown  in  Fig.  15.  The 
principal  parts  are: 

(a)  The  endosperm,  which  forms  the 
mass  of  the  kernel  and  is  made  up  of 
starch  and  protein  cells. 

(6)   The  aleurone  cells,  or  layer  of  large  square  cells  sur- 

53 


Fig.  15. — Longitudinal 
section  of  a  grain  of 
wheat. 

a,  endosperm; 

b,  aleurone  cells; 

c,  bran  coats; 

d,  gerna. 


54  FOOD 

rounding  the  endosperm.     These  are  rich  in  phosphorus  and 
gluten. 

(c)  The  hran  coats,  which  comprise  several  layers  outside 
of  the  aleurone  cells.  These  are  rich  in  mineral  matter. 
Here  is  also  found  more  cellulose  than  in  other  parts  of  the 
grain. 

(d)  The  germ,  or  embryo,  located  at  one  end  of  the  kernel, 
is  the  young  plant  which  grows  on  germination.  It  is  rich 
in  protein,  fat  and  mineral  matter. 

85.  The  Proteins  of  Wheat. — The  two  most  important 
proteins  found  in  wheat  are  glutenin  and  gliadin.  These 
are  united  chemically,  when  flour  is  kneaded  with  a  liquid, 
and  form  gluten. 

86.  The  Milling  of  Flour.— The  history  of  the  develop- 
ment of  the  milling  process  is  an  interesting  topic  for  home 
reading.  The  roller  process  now  in  use  yields  about  75  per 
cent  of  the  cleaned  wheat  as  white  flour.  The  remainder, 
called  shorts  and  bran,  is  used  for  feeding  cattle. 

The  high  grade  or  standard  flours  are  those  made  from 
wheat  yielding  not  only  a  high  percentage  of  gluten  but  a 
gluten  that  is  composed  of  the  proper  proportions  of  gliadin 
and  glutenin.  It  is  the  proportion  in  which  these  important 
profteins  occur,  quite  as  much  as  the  total  gluten  content 
of  the  flour,  which  makes  possible  a  large,  light,  and  porous 
loaf  of  bread. 

Whole  wheat  flour  is  wheat  meal  from  which  the  coarsest 
of  the  bran  has  been  removed.  It  contains  the  germ  and  a 
portion  of  the  aleurone  layer.  Graham  flour  is  the  unbolted 
wheat  meal.  Gluten  flour  is  the  spring  wheat  flour  after  a 
good  part  of  the  starch  has  been  removed. 

87.  Yeast  Bread. — Some  form  of  leavened  bread  is 
universally  depended  upon  as  a  staple  food.  It  is  the  most 
wholesome  and,  all  things  considered,  the  most  economical 
of  foods.  Yeast  bread  is  made  from  the  staple  grains, 
wheat  and  rye,  because  they  have  the  properties  which  are 
needed  to  form  a  light  and  porous  loaf.     Other  grains  are 


FLOUR  MIXTURES,  BREAD  AND  PASTRY  55 

often  combined  with  these  to  form  different  varieties  of 
bread. 

88.  Quick  Process  Bread. — Bread  made  with  a  large 
amount  of  yeast,  which  hastens  the  rising  and  shortens  the 
time  required,  is  called  quick  process  bread.  The  amount  of 
yeast  used  regulates  the  time  of  fermentation  but  does  not 
affect  the  quality  or  flavor  of  the  bread.  A  yeasty  odor  is 
due  to  insufficient  baking  or  over-fermentation  rather  than 
to  an  over  amount  of  yeast. 

Two  cakes  of  compressed  yeast  to  one  cup  of  liquid  is 
not  too  much  for  two  or  three  hour  bread.  The  quick 
process  plan  of  bread  making  is  a  decided  improvement 
upon  the  old,  slow  method  where  the  dough  was  liable  to 
become  sour. 

89.  Mixing  and  Kneading. — The  ingredients  for  bread 
should  be  mixed  thoroughly  and  only  enough  flour  should 
be  used  to  make  the  dough  stay  up.  The  softer  the  dough, 
the  better. 

(1)  Place  the  salt,  sugar  and  fat  in  the  mixing  bowl 
and  pour  over  them  the  scalded  milk  or  other  liquid.  When 
this  mixture  is  lukewarm,  add  the  yeast  rubbed  to  a  paste 
in  lukewarm  water  and  mix  thoroughly.  Add  flour  enough 
to  form  a  drop  batter,  and  beat  this  batter  until  bubbles 
of  air  begin  to  form  in  the  mass.  Then  add  gradually  the 
remainder  of  the  flour  or  enough  to  make  a  dough  that 
will  form  a  ball  around  the  mixing  spoon  and  leave  the 
sides  of  the  bowl  free  from  flour. 

(2)  After  the  dough  has  been  mixed  place  it  on  a  floured 
kneading  board  and  knead,  handling  lightly,  until  the 
dough  is  smooth  and  velvety  and  does  not  stick  to  the  hands 
or  board. 

(3)  Put  the  dough  aside  in  a  warm  place  to  rise.  The 
fermentation  period  is  the  most  important  of  all.  Bread 
should  not  be  allowed  to  rise  longer  than  is  required  for  it 
to  double  in  bulk.  If  fermentation  is  allowed  to  continue 
too  long,  the  dough  is  liable  to  become  sour. 


56 


FOOD 


(4)  When  the  dough  has  doubled  in  bulk,  the  gas  bub- 
bles may  be  removed  by  lightly  punching  the  mass  down 


Fig.  16. — Kneading  bread. 

in  the  bowl;    after  which,  let  the  dough  rise  again  until 
about  two-thirds  its  former  bulk. 

(5)  Mould  the  dough  into  loaves  by  stretching,  folding. 


FLOUR  MIXTURES,  BREAD  AND  PASTRY  57 

and  shaping  a  portion  to  fit  the  baking  tin.  Push  down  the 
corners  and  sides  to  make  an  even  loaf  and  let  the  loaf  rise 
again.  Moisten  the  loaf  on  top  to  prevent  a  hard  crust 
from  forming  during  the  rising  process. 

90.  Baking. — Bread  is  ready  for  the  oven  when  the  loaf 
has  settled  in  the  corners  and  the  dough  has  very  nearly 
doubled  in  bulk.  The  temperature  of  the  oven  should  be 
about  400°  F.  The  loaf  should  not  begin  to  brown  until 
it  has  been  in  the  oven  ten  minutes.  The  pan  should  be 
turned  around  after  three  minutes  baking  to  keep  the  loaf 
even.  Sixty  minutes  is  required  for  baking  the  average 
size  loaf. 

Rare  or  slack  baked  bread  resulting  from  under  bak- 
ing is  the  worst  and  most  frequent  fault  to  be  guarded 
against. 

91.  Effect  of  Ingredients  on  the  Loaf. — Too  much  flour 
will  cause  a  loaf  to  spUt  in  the  middle  in  baking.  Three 
cupfuls  of  flour  to  one  cupful  of  liquid  is  a  good  proportion. 
A  green  dough  (mixture  not  light  enough  when  put  in  the 
oven)  will  have  the  same  effect  as  too  much  flour.  Sugar 
hurries  along  the  action  of  the  yeast  by  supplying  quickly 
the  material  needed  to  produce  carbon  dioxide  (CO2). 

An  excess  of  salt  retards  the  fermentation  process. 
One  teaspoonful  of  salt  is  sufficient  for  one  loaf.  Fat  in 
large  amounts  has  the  same  effect  upon  the  mixture  as 
salt.  Not  over  one  tablespoonful  to  a  loaf  should  be 
allowed.  Fat  is  not  a  necessary  ingredient  in  well-made 
bread. 

92.  Rolls. — The  various  kinds  of  bread  dough  intended 
for  rolls  require  a  little  different  treatment  after  the  first 
rising.  The  punching  down  to  take  out  the  gas  should  be 
omitted.  Rolls  should  be  allowed  to  rise  until  at  least 
double  the  original  bulk  before  baking.  Rolls  are  baked  in 
eighteen  to  twenty  minutes  and  require  a  hotter  oven  than 
a  loaf  of  bread  will  stand. 


58 


FOOD 


Courtesy  of  Landers,  Frary  dk  Clark. 

Fig.  17. — Bread  mixer. 


93.  Bread   Mixers. — A   good    mixer    brings    about    the 

same  results  as  hand  kneading,  if  the  correct  proportion 

of  flour  and  liquid  is  used 
and  the  mixer  is  turned  for 
eight  minutes.  The  mixer 
undoubtedly  saves  time  and 
strength  in  making  large 
quantities  of  bread,  but  for 
less  than  three  loaves  the 
hand  method  is  easier. 

94.  Yeast. — Yeast  is  a 
tiny,  single-celled  plant. 
The  individual  plants  are 
round  or  oval  in  shape  as 
in  Fig.  18,  and  consist  of  a 
thin  cell  wall  of  cellulose 
filled  with  protoplasm.  The 

dark  spot  or    point    in    the    cell    is    called    the    nucleus. 
Under  normal  conditions  the  yeast  plant    develops  or 

grows  rapidly  by  the  process 

known  as  budding,   which  is 

one  of  the  simplest  forms  of 

cell  reproduction. 

95.  Sources  of  Yeast. — 
Wild  yeasts  are  abundant  on 
the  skins  of  fruits  and  vege- 
tables and  in  the  atmosphere. 

Cultivated  yeast, or  distillers' 
yeast,  intended  for  baking  purposes,  is  either  grown  in  quan- 
tity for  use  or  is  a  by-product  of  the  manufacture  of  malt 
liquors.  In  Fig.  19  is  represented  the  entire  process  of  making 
compressed  yeast  from  the  scouring  of  the  grains  to  the 
shipping  of  the  finished  product. 

96.  Commercial  Yeast. — The  usual  forms  in  which  yeast 
appears  in  the  market  are  compressed  yeast,  dry  yeast,  and 
liquid  yeast. 


Fig.  18. — Yeast  cells. 


FLOUR  MIXTURES,  BREAD  AND  PASTRY 


59 


BARLEY 
MALT 


SOURING 
TANK. 


FILTER  TU3 


SMALL 

LACTIC  ACID 

MAGH 


MIXING  MACHINE 

CARS  TO  AGENCIES 


REFRIGERATOR 


Courtesy  of  Fleischmann  Co. 

Fig.  19. — Manufacture  of  yeast. 


60  FOOD 

Compressed  yeast  is  to  be  preferred  when  it  can  be 
obtained.  It  has  the  advantage  of  providing  a  large  amount 
of  yeast  in  small  bulk,  but  it  will  not  keep  for  any  length  of 
time  and  should  be  fresh  when  used. 

In  dry  yeast  the  yeast  cells  have  been  mixed  with  tapioca 
or  other  flour  and  dried  before  being  put  up  in  packages. 
Dry  yeast  requires  a  longer  time  to  do  its  work  and  is  not 
as  effective  as  other  forms,  since  many  of  the  plants  are 
killed  by  the  drying  process. 

Liquid  yeast  may  be  made  at  home  or  bought  at  most 
bakeries.  Liquid  yeast  is  made  by  mixing  yeast  with  a 
liquid  which  contains  flour  and  sugar  or  other  food  for  the 
yeast  plant,  and  allowing  it  to  stand  in  a  warm  place  until 
the  mixture  is  filled  with  yeast  plants  as  shown  by  the 
bubbles  of  gas. 

Compressed  yeast  cakes  are  more  uniform  in  strength 
and  therefore  more  reliable  for  general  use  than  other  forms 
of  commercial  yeast. 

97.  Functions  of  Yeast  in  Bread  Making. — Since  yeast 
plants  develop  best  at  a  temperature  between  75°  and  90°  F., 
the  materials  for  bread  dough  should  be  lukewarm.  When 
the  materials  have  been  thoroughly  mixed,  the  mass  should 
be  kneaded  until  it  will  not  stick  to  the  hands  or  the  board 
and  is  elastic  to  the  touch.  It  should  then  be  set  aside  to 
allow  time  for  the  growth  of  the  yeast  plants.  Under 
proper  conditions,  that  is,  the  presence  of  warmth,  moisture, 
and  food,  the  yeast  plant  will  multiply  rapidly. 

Flour  contains  a  small  amount  of  sugar  and  also  a  ferment 
which  is  capable  of  changing  starch  into  sugar.  By  the 
action  of  the  yeast  this  sugar  is  broken  down  to  form  carbon 
dioxide  (CO2)  and  alcohol.  The  bubbles  of  gas  thus 
formed  are  entangled  in  the  dough,  causing  it  to  be 
spongy  and  light.  In  the  oven  these  bubbles  of  gas  expand 
and  increase  the  size  of  the  loaf.  The  heat  of  the  oven 
also  kills  the  yeast  plant  and  drives  the  alcohol  off  as  a 
vapor. 


FLOUR  MIXTURES,  BREAD  AND  PASTRY 


61 


98.  Digestibility  of  Bread. — The  nutrients  in  yeast 
bread  like  those  of  other  cereal  products  are  digested  and 
absorbed  with  relative  ease  and  thoroughness.  A  light, 
thoroughly  baked  crumb  is  digested  with  less  difficulty 
than  heavy  or  rare  baked  bread.  The  latter  tends  to  form 
a  waxy  mass  in  the  stomach,  which  resists  the  action  of  the 
digestive  fluids.  The  crust  is  partly  dextrinized  and  is 
crisp  and  dry.  In  this  state  the  change  from  dextrin  to 
maltose  is  easily  made  by  the  digestive  fluids. 

Hot  breads  are  less  easily  digested  than  yeast  breads 


Fig.  20. — Oatmeal  bread,  Rye  bread,  and  Corn  bread. 


because  the  warm  crumb  tends  to  form  a  waxy  mass  in  the 
stomach. 

99.  How  to  Know  Good  Bread. — The  loaf  should  be  of 
medium  size.  (A  large  loaf  is  liable  to  be  underdone  in  the 
center).  It  should  be  regular  in  shape,  rounded  on  top 
and  even  on  the  sides,  with  a  crisp,  golden-brown  crust. 

The  texture  of  the  crumb  should  be  fine  and  even.  (By 
texture  is  meant  the  size  and  .  uniformity  of  the  holes.) 
Large  holes  near  the  top  of  the  loaf  indicate  that  the  dough 
was  kept  too  warm  during  the  fermentation  process. 

The  color  of  the  crumb  should  be  white  or  creamy.     A 


62  FOOD 

gray  color  is  due  to  over  fermentation  or  to  a  cheap  grade 
of  flour. 

The  odor  should  be  "  wheaty."  A  yeasty  odor  suggest-s 
lack  of  sufficient  baking.  Underdone  or  slightly  sour  bread 
is  unwholesome. 

100.  Pastry. — Pie  crust,  tarts,  and  patties  belong  to  the 
stiff  dough  mixtures  and  contain  a  large  proportion  of 
shortening  or  from  one-third  to  one-half  as  much  as  of 
flour. 

Pastry  should  be  light,  flaky,  and  tender.  Since  pastry 
depends  upon  the  air  incorporated  into  the  mixture  for 
lightness,  this  property  is  increased  by  skillful  handling 
and  by  keeping  the  ingredients  at  a  proper  temperature. 
The  colder  the  ingredients  the  greater  the  expansion  in 
baking,  hence  the  greater  the  degree  of  lightness. 

Pastry  is  made  flaky  by  having  the  fat  in  rather  large 
flakes  in  the  flour  before  adding  the  liquid,  also  by  spreading 
more  fat  on  each  time  the  folding  and  rolling  process  takes 
place.  Tenderness  of  pastry  is  determined  by  the  amount 
of  fat  used  and  by  adding  the  least  possible  amount  of  mois- 
ture to  make  a  dough.  The  various  fats  such  as  butter, 
oleomargarine,  lard,  lard  substitutes,  nut  butters,  and  beef 
drippings,  may  be  used  alone  or  in  combination  for  this 
purpose. 

101.  Baking  Pastry. — Pies  should  be  baked  in  an  earthen- 
ware, granite  or  aluminum  pan,  or  better  still,  in  a  Pyrex 
plate.  The  upper  crust,  when  used,  should  have  several 
openings  to  permit  the  escape  of  the  steam  generated  in 
^)aking.  In  the  case  of  a  pie  with  only  a  lower  crust  it  is 
advisable  to  bake  the  crust  on  the  outside  of  the  inverted 
pan.  Prick  the  crust  in  several  places  with  a  fork  before 
baking,  to  allow  the  confined  air  to  escape  before  the  heat 
expands  it  and  spoils  the  shape  of  the  crust. 

The  temperature  of  the  oven  for  all  kinds  of  pastry 
should  be  what  is  termed  very  hot,  or  from  450°  F.  to  500°  F., 
until  the  crust  begins  to  brown.     Then  the  temperature 


FLOUR  MIXTURES,  BREAD  AND  PASTRY  63 

should  be  reduced  to  allow  for  the  thorough  cooking  of  the 
filling. 

102.  Digestibility  of  Pastry, — The  combination  of  so 
much  fat  as  is  commonly  used  in  pastry  with  flour  forms 
a  coating  of  fat  over  the  starch,  which  retards  the  action  of 
the  digestive  juices.  Soggy  pastry  is  not  so  easily  digested 
as  the  crisp  and  flaky  kind;  therefore,  for  one-crust  pies, 
the  crust  may  be  baked  before  the  filling  is  added  to  prevent 
the  crust  from  soaking  up  moisture  and  becoming  soggy. 

The  deep  fruit  pie  with  an  upper  crust  only  is  most 
desirable,  since  in  this  way  the  crust  may  be  crisp  and  flaky. 
This  pastry  also  affords  a  pleasing  way  of  serving  cooked 
fruits. 

SUGGESTIONS  FOR  LABORATORY  PRACTICE 

In  connection  with  the  study  of  the  text  of  the  preceding  chapter, 
make: 

Bfead,  short  and  long  process. 

Rolls,  plain  and  fancy. 

Nut  breads,  raisin  breads. 

Whole  wheat  bread,  corn  bread,  coffee  cake. 

Dutch  apple  cake. 

Pie  crust,  tarts,  patties. 

One-crust  pie,  two-crust  pie. 


CHAPTER  VIII 
VEGETABLES 

103.  Definition. — In  the  strictest  sense  of  the  word  cereals 
and  fruits  may  be  termed  vegetables,  but  what  is  commonly 
known  as  vegetables  are  the  plant  products  that  have  a 
very  high  water  content.  Those  containing  70  per  cent  or 
more  of  water  are  spoken  of  as  succulent. 

104.  Classification. — Vegetables  may  be  classified  in 
different  ways: 

(1)  As  to  the  part  of  the  plant  used:  Seeds;  roots;  tubers; 
bulbs;   stems;   leaves;   flowers;   fruit. 

(2)  As  to  co7nposition:  (a)  those  containing  much  water; 
(6)  those  containing  much  starch;  (c)  those  containing 
much  protein. 

(3)  As  to  flavor:   (a)  mild  in  flavor;   (h)  strong  in  flavor. 

105.  Composition. — The  foodstuff  other  than  water  that 
appears  in  greatest  abundance  in  vegetables  is  carbohydrate, 
either  in  the  form  of  starch  or  sugar.  Protein  is  present 
in  varying  amounts  in  the  form  of  globulin  and  vegetable 
casein,  the  latter  sometimes  called  legumin.  Comparing  the 
protein  of  vegetables  with  that  of  animals,  the  following 
distinctions  may  be  made : 

(1)  Vegetable  protein  is  deficient  in  nucleo  protein,  while 
animal  protein  is  rich  in  this  material. 

(2)  Globulin,  the  form  in  which  the  protein  occurs  in 
vegetables,  contains  less  sulphur  than  the  animal  albumin, 
and  is  insoluble  in  pure  water  though  soluble  in  a  salt  solu- 
tion. 

(3)  Vegetable  protein  yields,  on  decomposition,  a  much 
higher  percentage  of  glutamic  acid  than  animal  protein. 

64 


VEGETABLES  65 

Extractives  are  present  in  vegetables  and  belong  to  the 
class  of  chemical  substances  known  as  amines. 

Mineral  Matter,  the  presence  of  which  adds  so  much  to 
the  nutritive  value  of  many  vegetables,  occurs  largely  in 
the  form  of  potash  and  phosphorus;  but  as  these  salts  do 
not  appear  as  chlorides,  common  salt  is  a  welcome  addition 
to  a  vegetable  diet.  Small  amounts  of  citrates,  phosphates, 
and  silicates  of  lime  are  also  found,  and  sulphur  occurs  in 
such  vegetables  as  onions,  cabbage,  and  the  legumes. 

Fat  occurs  in  vegetables  only  in  minute  quantities  and 
in  the  form  of  olein. 

106.  Food  Value. — With  the  exception  of  a  few  of  the 
starchy  vegetables  and  the  legumes,  plant  substances  are 
not  considered  very  nutritious,  but  they  are  necessary  as 
body  regulators  and  to  give  flavor,  bulk  and  variety  to  the 
diet.  They  yield  a  certain  amount  of  energy  in  the  body 
at  comparatively  low  cost  in  normal  times. 

107.  Digestion  of  Vegetables. — Owing  to  the .  large 
amount  of  cellulose  present  in  vegetables,  they  are  more 
difficult  of  digestion  than  animal  food,  and  experiments 
have  shown  that  their  completeness  of  digestion  is  very 
much  less  than  that  of  animal  foods.  The  formation  of 
undesirable  gases  from  the  sulphur  present  in  strong  flavored 
vegetables  causes  the  flatulence  experienced  by  many  peo- 
ple after  a  too  liberal  diet  of  these  varieties. 

108.  The  Selection  of  Vegetables. — In  selecting  vege- 
tables buy  those  that  are  in  season  as  they  are  then  much 
better  flavored  and  less  expensive. 

Buy  by  weight  rather  than  by  measure;  choose  firm, 
crisp  vegetables,  heavy  for  their  size  and  of  medium  size 
only,  as  large  ones  are  apt  to  be  old  and  fibrous.  See  that 
the  skin  is  unbroken.  Earth  adhering  to  vegetables  is 
evidence  that  they  have  not  been  freshened  by  soaking  in 
water. 

109.  Cooking  Vegetables. — The  changes  that  are  to  be 
effected  by  cooking  are  as  follows: 


< 


66  FOOD 

(1)  The  cellular  tissue  is  to  be  loosened  and  softened. 

(2)  The  starch  granules  must  absorb  water  and  swell. 

(3)  Pleasant  flavors  are  to  be  developed  and  unpleasant 
ones  dissipated. 

The  method  of  cooking  should  he  such  as  to  lessen  the 
waste  as  much  as  possible.  Cooking  in  water,  the  way  most 
commonly  employed,  effects  a  withdrawal  of  nutrients, 
especially  the  mineral  matter — a  loss  which  occurs  to  a 
much  less  extent  in  steaming,  and  not  at  all  in  baking. 
Keeping  vegetables  whole  while  boiling  minimizes  the  waste. 

All  green  vegetables,  roots,  and  tubers  should  l^e  crisp 
and  firm  before  cooking.  If  they  are  not  they  should  be 
allowed  to  stand  in  very  cold  water  about  one  hour.  All 
vegetables  should  be  most  carefully  cleaned  before  cooking. 
Those  in  heads,  such  as  cabbage,  Brussels  sprouts,  and  cauli- 
flower, should  be  placed  head  down  in  cold,  salted  water 
to  which  a  little  vinegar  has  been  added.  This  will  draw 
out  any  animal  life  that  may  be  present  in  them. 

All  vegetables  except  the  legumes  are  best  cooked  by 
putting  into  rapidly  boiling  water  and  keeping  them  at 
this  temperature  until  the  vegetables  are  tender.  The 
cover  of  the  saucepan  should  be  partly  off  to  allow  for  ven- 
tilation and  the  evaporation  of  the  disagreeable  volatile 
gases  developed  by  the  heat.  Over-cooking  is  to  be  avoided, 
as  it  destroys  the  chlorophyl  and  other  coloring  matter 
and  injures  the  substances  which  give  the  pleasant  flavors. 

The  practice  of  adding  bicarbonate  of  soda  to  the 
water  in  which  vegetables  are  to  be  cooked  is  no  longer 
advised.  .It  has  been  found  by  experiment  that  cooking 
in  an  alkaline  solution  dissolves  some  of  the  vitamines, 
thereby  decreasing  the  nutritive  value  of  the  vegetables. 

110.  Blanching  Vegetables. — Blanching  is  supposed  to 
improve  the  flavor  by  removing  the  strong,  acrid  taste  of 
some  vegetables,  to  harden  the  tissue,  and  to  set  the  color. 
This  is  done  by  dipping  the  vegetables,  which  have  been 
thoroughly  cleaned  and  placed  either  in  cheese-cloth  or  in  a 


VEGETABLES 


67 


wire  basket,  into  rapidly  boiling  water,  covering  and  keep- 
ing at  this  point  from  five  to  ten  minutes.  Drain,  and  if 
the  vegetables  are  not  to  be  used  for  canning  (in  which  case 
they  are  plunged  immediately  into  cold  water),  put  them 
into  a  saucepan  with  as  little  water  as  possible,  partly  cover 
and  allow  to  cook  gently  until  tender,  when  most  of  the 
water  should  have  evaporated.  Salt,  pepper,  and  butter 
should  be  added  before  serving. 

111.  Preserving  Vegetables. — Vegetables  are  preserved 
in  a  variety  of  ways,  although  canning  and  drying  are 
perhaps  the  most  popular.  These  processes  will  be  treated 
at  greater  length  in  a  separate  chapter.  Simply  packing 
fresh  vegetables  between 
layers  of  salt  will  preserve 
them.  Salt  with  the  addi- 
tion of  vinegar  is  used  in 
pickling.  Commercial  cold 
storage  has  done  much  to 
conserve  the  surplus  in 
vegetables  as  in  other  foods, 
and  is  of  course  effective  in 
checking  bacterial  growth. 
Preserving  vegetables  by 
the  use  of  such  preserva- 
tives as  borates,  benzoates, 
etc.,  is  to  be  condemned. 
The  so-called  winter  vege- 
tables such  as  turnips,  cab- 
bage, onions,  carrots,  par- 
snips and  beets  may  be  kept 
in  good  condition  by  being 
buried  or  stored  in  a  cool 
place. 

112o  Legumes. — The  le- 
gumes belong  to  the  pulse 
family.     They  are  the  fruit  of  the  plant  and  are  usually  in 


Fig.  21.— Lentils. 
(Farmer's  Bulletin  121.) 


68 


FOOD 


the  shape  of  a  pod.  There  are  many  kinds,  but  those  used  as 
vegetables  are  peas,  beans,  and  lentils.  The  unripe  peas 
and  beans  and  the  edible  pods  of  the  latter  contain  much 
water  and  are  classed  as  succulent  vegetables.  While  they 
are  not  as  rich  in  nutrients  as  the  matured  ones,  they  are 


Fig.  22. — Peanut  vine  showing  nodules  on  the  roots. 
(Bulletin  121.) 


more   delicate   in  flavor   and   more    easily    digested.      The 
lentil  is  never  eaten  except  when  fully  ripe. 

113.  Food  Value  of  Legumes. — The  legumes,  except  in 
war  times,  are  a  particularly  cheap  source  of  protein  or 
nitrogen  to  the  body.  They  are  the  only  plants  that  can 
make  use  of  the  nitrogen  of  the  air  to  build  their  own  tissue, 
and  for  this  purpose  their  roots  are  furnished  with  nodules 
thickly  populated  by  nitrogen-fixing  bacteria.      The  dried 


VEGETABLES  69 

legumes  are  fully  matured  and,  while  deficient  in  flavor  they 
contain  a  high  percentage  of  protein.  In  cases  where  they 
can  be  digested  without  too  much  difficulty  the  legumes  may 
be  used  as  a  substitute  for  the  more  expensive  animal  foods. 

114.  Cooking  Legumes. — The  green  legumes  are  cooked 
in  the  same  way  as  other  fresh  vegetables;  but  the  way 
in  which  the  dried  ones  are  cooked  greatly  influences  their 
digestibility.  Dried  legumes  should  be  cleaned,  then  soaked 
over  night  in  cold  water,  and  in  the  morning  cooked  in  this 
same  water  until  tender.  Making  the  legumes  into  a  puree 
renders  them  more  available  as  a  source  of  nourishment. 
It  separates  the  more  digestible  pulp  from  the  skin.  The 
digestibility  of  legumes  is  increased  if  they  are  eaten  in 
combination  with  other  food  rather  than  alone. 

115.  Soy  Beans. — The  soy  bean,  Fig.  23,  which  is  some- 
times spoken  of  as  the  Togo  bean,  has  been  used  as  food  in 
China  and  Japan  since  ancient  times;  but  in  this  country 
its  use  as  such  is  just  beginning. 

Up  to  the  present  time  it  has  served  only  as  a  fertiUzer, 
as  food  for  hogs,  or  as  a  source  of  oil  to  be  used  as  a  sub- 
stitute for  more  expensive  oils. 

Composition. — Like  most  legumes  the  soy  bean  is  very 
rich  in  protein.  Compared  with  the  cereals  it  contains 
three  limes  as  much  protein  as  wheat  or  rye  flour,  and  five 
times  as  much  as  corn  flour.  The  amount  of  fat  present 
in  the  soy  bean  is  ten  times  as  much  as  is  present  in  any 
cereal.     It  is  deficient  in  carbohydrates. 

Appearance. — In  appearance  the  soy  bean  is  round  and 
yellow,  somewhat  similar  to  the  garden  pea.  There  arc 
two  hundred  varieties,  but  it  is  the  yellow-seeded  variety 
which  is  best  for  food. 

Cooking. — The  soy  bean  may  be  cooked  in  a  variety  of 
ways,  and  may  be  combined  to  advantage  with  many  other 
foods  such  as  rice,  cheese,  tomatoes,  and  corn.  It  may  be 
soaked  over  night  and  baked  the  same  as  the  navy  bean, 
but  without  the  addition  of  fat  of  any  kind. 


70 


FOOD 


Courtesy  of  Extension  Department. 

Fig.  23. — Soy  beans. 

The  plant  to  the  left  inoculated,  the  one  to  the  right  uninoeulated. 

(From  McCall's  "  Studies  of  Crops.") 


VEGETABLES  71 

116.  Tubers. — A  tuber  is  a  short,  fleshy,  underground 
stem.  The  common  edible  tubers  include  white  potatoes 
Jerusalem  artichokes,  and  sweet  potatoes. 

While  white  potatoes  are  rich  in  starch  and  are,  there- 
fore, a  source  of  energy  to  the  body,  they  are  chiefly  valuable 
for  their  antiscorbutic  properties,  due  to  the  nature  of  the 
mineral  matter  present.  Very  new  and  very  old  potatoes 
contain  less  starch  and  more  soluble  sugar,  which  accounts 
for  their  lack  of  mealiness  when  cooked.  After  potatoes 
begin  to  sprout,  the  starch  content  is  changed  to  glucose 
by  a  ferment  present  in  them. 

Jersualem  artichokes  contain  no  starch,  and  so  resemble 
the  turnip  rather  than  the  potato.  They  do  contain  a  small 
amount  of  sugar  and  another  form  of  carbohydrate  known 
as  inulin. 

Sweet  potatoes  are  about  the  same  in  composition  as  the 
white,  containing  a  little  more  sugar  and  being  somewhat 
laxative. 

117.  The  Dasheen. — This  comparatively  little  known 
vegetable  is  of  the  starchy  variety  and  rather  closely  resem- 
bles the  potato  (Fig.  24),  though  it  is  more  dehcate  in 
flavor  and  contains  less  water.  After  cooking,  the  flesh 
becomes  gray  or  violet. 

Any  method  of  cooking  which  may  be  applied  to  the 
potato  may  likewise  be  applied  to  the  dasheen.  If  scraped 
before  cooking,  it  should  be  handled  under  water  to  which 
sal-soda  has  been  added  (one  teaspoon  to  one  quart  of 
water).  This  is  done  to  prevent  the  juice  from  the  outer 
layer  from  exerting  an  irritating  effect  upon  the  hands. 

118.  Roots. — The  roots  most  commonly  used  as  foods 
are  beets,  radishes,  turnips,  carrots,  salsify,  parsnips  and 
celeriac. 

Beets,  carrots  and  turnips,  when  used  as  summer  vege- 
tables, are  the  quickly  grown  variety  and  are  gathered 
while  small.  When  intended  for  winter  use,  they  must  be 
allowed  to  mature  or  they  cannot  be  successfully  stored. 


72 


FOOD 


Celeriac  is  a  variety  of  the  familiar  celery  but  is  culti- 
vated for  its  turnip-like  root,  rather  than  for  its  stalk. 

119.  Bulbs. — The  underground  leaf-buds  of  certain 
plants  are  known  as  bulbs.  Onions  are  the  most  generally 
used  of  this  type,  but  others  used  more  sparingly  and  for 
flavor  only,  are  garlic,  leek,  shallot  and  chives. 

120.  Leaves,  Stems,  and  Shoots. — The  edible  portions  of 
cabbage,    lettuce,    celery,   asparagus,    and   spinach   are  the 


Fig.  24.— The  Dasheen. 
(Journal  of  Home  Economics.) 

leaves,  stems  or  shoots  of  the  plants.  While  the  food  value 
of  these  vegetables  is  not  high,  they  are  refreshing  and  a 
pleasant  source  of  mineral  matter.  Contrary  to  custom, 
leaf  vegetables  should  be  cooked  in  as  little  water  as  pos- 
sible and  the  water  saved  as  it  has  been  found  to  contain 
valuable  vitamines. 

121.  Fruit. — The  seed-bearing  part  of  a  plant  is  called 
the  fruit.  The  common  vegetables  used  as  foods,  which  are 
known  to  the  botanist  as  the  fruits  of  the  plants,  are  torn  a- 


VEGETABLES 


73 


74  FOOD 

toes,    okra,    squash,    pumpkin,    cucumber,    egg   plant    and 
peppers. 

122.  Flower  Buds. — Among  the  food  plants  of  which 
the  parts  eaten  are  the  flower  buds  may  be  mentioned: 
cauliflower,  broccoli  and  French  artichokes. 

Broccoli  is  a  variety  of  cabbage.  It  resembles  the  cauli- 
flower but  has  a  taller  stem. 

French  artichokes  are  large  flower  buds;  the  buds  must 
be  used  before  they  are  open.  The  edible  parts  are  the 
thickened  portion  at  the  base  of  the  scales  and  the  part  to 
which  the  leaf -like  scales  are  attached. 

Brussels  sprouts  are  a  variety  of  cabbage  having  about  the 
same  composition  as  the  cabbage. 

Kohl-rabi  is  very  similar  to  the  turnip  in  appearance 
and  flavor. 

Okra  is  a  plant  much  cultivated  in  the  South  for  its 
young,  mucilagenous  pods.  It  has  very  little  food  value 
and  is  generally  used  for  flavoring  soups.  In  localities 
where  it  is  grown  the  very  young  seeds  are  sometimes  cooked 
in  the  same  way  as  green  peas.  The  tender  pods  may  be 
boiled  and  served  as  salad. 

123.  Green  Vegetables. — The  so-called  green  vegetables, 
or  salad  plants,  are  those  usually  eaten  without  cooking. 
Lettuce  is  the  best  example  and  most  widely  used  of  these, 
but  endive,  cress,  mint,  green  peppers,  celery,  cucumbers, 
and  escarole  are  much  used. 

Green  vegetables  are  composed  largely  of  water  (90  per 
cent  or  more)  and  cellulose.  Their  most  valuable  con- 
stituent, infinitesimal  though  it  may  be  in  amount,  is  mineral 
matter.  This  exists  largely  in  the  form  of  potassium  salts, 
though  small  amounts  of  iron  are  also  present  and  certain 
substances  which  impart  an  agreeable  flavor. 

124.  Digestion  and  Food  Value  of  Green  Vegetables. — 
Green  vegetables  are  not  easy  of  digestion  except  when 
young.  With  age  the  amount  of  cellulose  increases,  making 
them  tough  and  stringy.     Owing  to  the  amount  of  water 


VEGETABLES 


75 


Fig.  26. — Brussels  sprouts. 
(From  Yeaw's  Market  Gardening) 


76  FOOD 

they  contain,  green  vegetables  must  be  eaten  while  fresh, 
as  they  wilt  easily,  due  to  the  evaporation  of  some  of  this 
water. 

None  of  these  salad  plants  are  of  high  nutritive  value, 
but  they  are  cooling,  antiscorbutic,  and  gently  laxative. 
Because  of  their  low  nutritive  value  they  may  be  eaten  in 
addition  to  the  protein  and  fuel  foods  without  unduly 
increasing  the  total  amount  of  food  consumed.  This  prop- 
erty makes  them  very  useful  in  the  limited  diet  of  those 
who  are  reducing. 

Whether  green  vegetables  are  to  be  cooked  or  not, 
they  must  be  very  carefully  cleaned  by  soaking  in  very 
cold,  salted  water  and  removing  all  decayed  parts.  Some 
authorities  advise  dipping  in  boiling  water  for  one  minute 
in  order  to  kill  any  living  organisms  that  may  be  present. 

125.  Lettuce,  Roumaine  and  Escarole. — These  vegetables 
are  cultivated  for  their  pleasant  flavor  and  are  in  the  market 
all  the  year  round  as  they  can  be  grown  successfully  under 
glass. 

SUGGESTIONS  FOR  LABORATORY  PRACTICE 

In  connection  with  the  study  of  the  text  of  the  preceding  chapter: 
Cook  potatoes,  tomatoes,  carrots,  cabbage,  onions,  or  any  vegetable 
in  season. 


CHAPTER  IX 
FRUITS 

126.  Definition. — In  a  restricted  sense  all  seed-bearing 
portions  of  plants  are  termed  fruits,  but  in  the  usual  sense 
the  term  fruit  is  used  to  indicate  only  those  seed-bearing 
portions  containing  a  large  amount  of  water  and  a  small 
amount  of  dry  matter  in  the  form  of  sugar  and  non-nitro- 
genous compounds.  Any  food,  for  example,  rhubarb, 
which  takes  the  same  place  in  the  diet,  may  be  classed  as  a 
fruit. 

127.  Composition. — Fruits,  like  vegetables,  contain  a 
large  amount  of  water.  Some  authorities  go  so  far  as  to 
classify  them  according  to  their  water  content,  those  having 
more  than  80  per  cent  of  water  being  classed  as  "flavor 
fruits.'' 

Another  more  common  classification  is  as:  stone  fruits; 
pome  fruits;   and  berries. 

The  most  important  solid  nutrient  of  fruit  is  carbo- 
hydrate. This  occurs  as  a  form  of  sugar;'  cane  sugar,  grape 
sugar  (glucose),  or  fruit  sugar  (levulose).  The  last  two 
sugars  are  usually  found  together  in  about  equal  proportions 
and  are  sometimes  referred  to  as  "invert  sugar." 

Fatf  except  in  the  case  of  such  fruits  as  the  olive  and 
the  avacado  or  alligator  pear,  exists  in  fruits  in  such  small 
quantities  as  to  be  negligible. 

Mineral  mattery  b.  most  important  constituent  of  all 
fruit,  is  found  in  the  form  of  potassium  salts,  phosphorus, 
lime,  and  iron.  Acids  are  present  in  varying  amounts, 
from  1  to  2  per  cent  in  apples  to  7  per  cent  in  lemons.  The 
most  common  fruit  acids  are  malic,  citric,  and  tartaric. 

77 


78  FOOD 

Protein  is  found  in  fruits  only  in  very  small  amounts. 

128.  Digestibility. — The  ease  with  which  fruits  are 
digested  depends  upon  the  nature  of  the  fruit  and  the 
degree  of  ripeness  and  freshness.  Unripe  fruits  are  indi- 
gestible because  of  the  large  amount  of  cellulose  present, 
and  because  the  large  amount  of  acid  acts  as  an  irritant 
to  the  digestive  organs.  Overripe  fruits  are  indigestible 
because  of  the  fermentation  products  which  have  begun 
to  form. 

129.  Food  Value. — ^While  fruits  are  not  a  source  of  much 
nourishment  to  the  body,  they  yield  energy  and  are  of 
inestimable  value  as  body-regulators.  Their  acids  stimulate 
the  flow  of  the  digestive  juices,  and  because  of  the  organic 
potassium  compound  which  they  contain,  fruits  when  oxidized 
in  the  body,  leave  basic  or  alkaline  salts  which  help  to  neu- 
tralize the  undesirable  acids  that  are  a  necessary  accompani- 
ment of  all  body  metabolism. 

Fruits  containing  malic  or  citric  acid  serve  as  a  laxative 
when  taken  before  or  at  the  beginning  of  breakfast.  Fruits 
tend  to  lessen  intestinal  putrefaction,  because  of  their 
fibrous  nature  which  stimulates  peristalsis,  and  because 
they  furnish  a  condition  unfavorable  to  the  growth  of 
intestinal  bacteria. 

130.  Selecting  Fruit. — Fruits  owe  much  of  their  popu- 
larity to  their  pleasant  flavor.  This  flavor  is  due  to  ethereal 
substances  that,  as  their  name  implies,  may  easily  be  lost. 
Therefore,  fruits  that  are  not  perfectly  fresh  show  the  fact 
by  loss  of  flavor  as  well  as  by  loss  of  color.  As  fruits  deterior- 
ate, their  coloring  matter  undergoes  various  chemical 
changes  which  give  the  faded,  dull  appearance  noticeable 
in  fruit  of  inferior  quality.  Fruit  in  prime  condition 
should  be  firm  and  heavy  in  proportion  to  its  size,  and  the 
skin  should  be  unbroken. 

131.  Preparation  and  Cooking. — Because  of  the  great 
improvement  in  culture,  storage  facilities,  and  transportation, 
the   season   for   fresh   fruit   has   been   greatly   lengthened. 


FRUITS  79 

Moreover,  commercially  dried  fruit  has  come  into  greater 
use,  so  that  fruit  of  some  kind  is  now  considered  a  necessary- 
part  of  the  daily  ration. 

As  so  much  fruit  is  eaten  uncooked,  great  care  should 
be  observed  in  preparing  it;  otherwise  it  may  be  a  means 
of  conveying  harmful  organisms  to  the  body.  The  popular 
idea  that  fruit  must  not  be  washed  no  longer  prevails.  It 
should  be  carefully  washed,  but  only  just  before  using, 
as  most  fruit  is  apt  to  mould.  Fruits  may  be  cooked  in 
various  ways,  and  in  some  cases  the  digestibility  is  increased 
by  so  doing,  but  the  fact  must  be  borne  in  mind  that  cooking 
often  injures  the  flavor  and  changes  the  nature  of  the  salts 
and  acids  present.  Fruit  discolors  when  pared  and  exposed  V 
to  the  air.  This  is  due  to  the  action  of  the  oxydases  (natural 
ferments)  in  the  fruit,  upcn  the  tannin  in  the  fruit,  in  the 
presence  of  air. 

The  utensils  used  in  cooking  fruit  must  be  of  a  mate- 
rial not  easily  acted  upoi;i  by  acids.  A  silver  knife  should 
always  be  used  in  preparing  fruits. 

132.  Storing. — Fruit  to  be  stored  must  be  in  perfect 
condition,  firm  and  free  from  the  slightest  bruise.  It  may 
be  packed  in  barrels  and  kept  in  a  clean  cool  place,  not  dry 
enough  to  cause  the  fruit  to  shrivel  or  moist  enough  to 
cause  fermentation.  The  store  room  should  be  well  ven- 
tilated, as  fruits  quickly  absorb  odors.  Fruits  keep  best 
when  wrapped  individually  in  tissue  paper. 

133.  Preserving. — Fruits  may  be  preserved  by  canning, 
drying,  pickling  and  candying,  and  in  the  form  of  jellies, 
jams  and  marmalades.  These  processes  are"  considered 
under  a  separate  heading. 

134.  Dried  Fruits. — Since  the  drying  of  fruit  has  become 
such  an  important  industry  on  our  western  coast,  such 
fruits  as  peaches,  apricots,  prunes,  figs,  and  raisins  are  now 
easily  obtained  at  all  times,  and  are  found  to  be  cheaper  in 
proportion  to  the  solids  they  contain  than  are  the  fresh 
fruits. 


80  FOOD 

When  properly  cooked,  dried  fruits  are  a  palatable  and 
useful  addition  to  the  diet.  They  should  be  thoroughly 
cleaned,  allowed  to  remain  over  night  in  sufficient  water 
to  cover  them,  then  cooked  in  the  same  water  until  tender, 
with  little  or  no  sugar.  Prunes  are  best  flavored  when 
cooked  without  sugar. 

135.  Jellies,  Jams,  and  Marmalades. — These  methods 
of  preserving  are  particularly  applicable  to  fruits  and  fruit 
juices.  Their  solidity  and  the  presence  of  sugar  in  fairly 
large  amounts,  render  them  impervious  to  bacterial  action. 
Their  solidity  is  due  to  the  existence  in  fruit  of  a  carbo- 
hydrate substance  called  pectin,  which  closely  resembles 
and  has  many  of  the  properties  of  starch. 

136.  Nuts. — The  increasing  popularity  of  nuts  as  a  part 
of  the  diet  is  probably  due  to  a  growing  appreciation  of 
their  food  value  and  appetizing  qualities,  as  well  as  to  a 
wider  knowledge  of  the  various  ways  in  which  they  may  be 
used  to  advantage. 

Composition. — Owing  to  their  deficiency  in  water,  nuts 
offer  a  very  concentrated  form  of  nourishment.  They  are 
a  rich  source  of  proteins,  some  (the  peanut  for  example) 
yielding  as  high  as  29.8  per  cent  of  this  foodstuff.  In  the 
analysis  of  thirteen  different  varieties,  half  the  edible  portion 
of  the  nut  consisted  of  fat  or  oil.  Carbohydrate  does  not 
appear  to  any  extent  except  in  the  chestnut.  Mineral 
matter  is  an  important  constituent  of  all  nuts,  walnuts  and 
almonds  being  especially  rich  in  phosphorus. 

Flavor. — The  flavor  of  nuts  is  largely  dependent  upon  the 
nature  of  the  oil  present,  though  in  some  instances  special 
flavoring  substances  are  also  present.  This  oil  becomes 
rancid  quickly  and  gives  the  intensely  disagreeable  taste 
to  spoiled  nuts. 

Digestibility. — The  difficulty  experienced  by  some  in 
digesting  nuts  is  probably  due  to  improper  mastication  and 
to  the  indiscriminate  use  of  nuts  at  such  times  as  the  end 
of  a  meal  or  late  at  night.     To  their  concentrated  form 


FRUITS  81 

also  may  be  attributed  some  of  the  difficulty  in  their  diges- 
tion. This  is  obviated  if  nuts  are  eaten  at  the  proper  time 
and  in  proper  relation  to  the  rest  of  the  diet.  Experiments 
in  the  use  of  almonds,  peanuts,  pecans,  and  walnuts  have 
brought  out  the  fact  that,  in  a  fruit  and  nut  diet,  the  nut 
protein  was  digested  quite  as  easily,  though  not  quite  so 
completely,  as  the  protein  of  milk. 

137.  The  Use  of  Salt  with  Nuts.— While  the  addition 
of  salt  to  nuts  may  improve  their  flavor,  no  proof  exists 
that  it  in  any  way  facilitates  their  digestion,  as  it  is  so 
popularly  supposed  to  do. 

138.  Food  Value  of  Nuts. — Because  of  the  composition 
of  nuts,  vegetarians  have  been  in  the  habit  of  using  them 
in  their  diet  as  a  source  of  protein  and  fat.  At  the  present 
time  many  others  are  gradually  being  forced  to  adopt  the 
same  plan,  owing  to  the  constantly  increasing  cost  of  animal 
food.  In  the  use  of  nuts,  however,  satisfactory  results 
can  be  obtained  only  by  a  thoughtful  arrangement  of  the 
menu.  The  nuts  should  be  made  to  take  a  definite  place 
in  the  meal  rather  than  to  supplement  an  otherwise  suffi- 
cient one.  Because  of  their  concentrated  nature  they 
should  be  combined  with  foods  of  a  bulky  type,  such  as 
vegetables,  fruits,  etc.  Those  of  high  protein  and  fat  con- 
tent should  be  combined  with  the  various  carbohydrate 
foods,  while  the  carbohydrate-containing  chestnut  may  be 
advantageously  used  with  milk,  meat,  and  eggs.  Nut 
butter,  notably  peanut,  is  very  digestible  owing  to  the  fine 
division  of  the  nut  substance,  and  is  in  a  form  often  relished 
by  people  opposed  to  nuts  in  other  forms.  Peanut  oil 
may  be  substituted  for  olive  oil  in  dressing  salads. 

139.  Use  of  Nuts  in  Cooking. — Nuts  are  more  often 
eaten  raw  than  cooked,  though  some,  like  the  peanut  and 
chestnut,  are  much  improved  in  flavor  by  roasting.  Nuts 
are  now  coming  to  be  used  very  often  in  the  making  of 
soups,  stuffings,  salads,  breads,  cakes,  etc. 

140.  Storing  Nuts. — Nuts  should  be  stored  in  a  dry  place, 


82  FOOD 

because    dampness    quickly   makes    them    rancid.     Shelled 
nuts  must  be  carefully  protected  from  insects. 

EXPERIMENTS 

Experiment  1.  The  Test  for  Pectin. — Add  two  teaspoonfuls  of 
alcohol  to  two  teaspoonfuls  of  cooked  fruit  juice.  Mix  thoroughly. 
The  formation  of  a  gelatinous  mass  indicates  the  presence  of  pectin. 

Experiment  2.  The  Test  for  Tannin. — Extract  the  juice  from 
unripe  fruit,  filter  and  add  ferric  chloride.  A  black  color  indicates  the 
presence  of  tannin. 

SUGGESTIONS  FOR  LABORATORY  PRACTICE 

In  connection  with  the  study  of  the  text  of  the  preceding  chapter: 
Cook  fruits  in  various  ways,  as  boiling,  baking,  scalloping,  stewing. 


CHAPTER  X 
FATS  AND   OILS 

141.  Composition. — Fats  and  oils  are  a  combination  of 
the  elements  carbon,  hydrogen,  and  oxygen.  The  oxygen 
is  less  in  proportion  to  the  carbon  than  in  the  carbo- 
hydrates, which  accounts  for  the  greater  yield  of  energy  by 
fats  and  oils.  The  fats  and  the  oils  were  the  first  of  the 
organic  foodstuffs  to  have  their  composition  determined. 
Upon  study  it  was  found  that  all  fats  are  formed  by  the 
chemical  union  of  fatty  acids  and  glycerol  or  glycerin. 
The  kind  of  fat  depends  upon  the  fatty  acids  in  the  com- 
bination. The  common  fatty  acids,  beginning  with  that 
having  the  lowest  melting-point,  are  butyric,  oleic,  palmitic, 
and  stearic. 

Glycerol  has  the  power  to  unite  with  one,  two,  or  three 
fatty  acids  to  form  simple  or  complex  glycerides. 

142.  Properties. — As  to  physical  properties  the  fats 
and  oils  differ  in  that  fats  are  solid  at  ordinary  temperature 
while  oils  are  the  reverse  or  liquid  at  ordinary  temperatures. 
The  chemical  difference  in  the  various  fats  and  oils  depends 
upon  the  fatty  acid  predominating.  In  tallow  and  lard 
the  glycerides  are  mainly  stearin  and  palmatin  with  only  a 
small  percentage  of  olein,  but  in  the  softer  fats  and  oils, 
olein  predominates. 

In  butter  the  glyceride  is  chiefly  butyrin.  Small  amounts 
of  various  other  glycerides  are  found  in  combination. 

Fats  have  a  varying  melting-point  because  they  are 
mixtures  rather  than  pure  glycerides.  Hard  or  animal 
fats  have  the  highest  melting-points  and  oils  or  liquid  fats  a 
low  melting-point. 

83 


84  EboD 

143.  Function  of  Fats  in  Nutrition. — Fats  are  broken 
down  in  normal  metabolism  and  yield  twice  as  many  calories 
of  heat  per  gram  as  carbohydrate  and  protein.  The  primary 
use  of  fats  in  the  body  is  as  a  fuel  or  heat  producer,  only 
excess  amounts  being  stored  as  fat  in  the  body  tissues. 

As  a  building  material  fat  is  changed  into  the  composi- 
tion of  the  protoplasm  of  the  cells  or  is  stored  as  body  fat 
in  certain  parts  of  the  body.  The  tissues  around  the  liver 
and  the  abdomen  are,  as  a  rule,  the  first  to  store  this  excess 
fat. 

Some  fats  hold  in  solution  substances  that  are  essential 
in  normal  nutrition  and  thus  serve  as  body  regulators.  The 
fat  of  milk,  of  egg  yolk,  and  to  some  extent  the  soft  fat  of 
beef,  belong  to  this  class.  A  deficiency  of  these  foods  in 
the  diet  will  be  shown  in  the  slow  growth  and  development 
of  the  body. 

144.  Digestibility  of  Fats. — The  fats  and  oils  are  changed 
back  to  fatty  acids  and  glycerin  in  the  digestive  tract,  and, 
as  such,  are  absorbed  through  the  intestinal  walls  into  the 
lymphatics.  From  there  they  go  into  the  general  circula- 
tion of  the  blood  and  are  found  again  as  a  fat.  The  reuniting 
of  the  parts  takes  place  at  the  time  of  absorption  into  the 
blood  stream. 

It  is  now  a  well  established  fact  that  the  fineness  of  the 
emulsion  into  which  a  fat  is  changed  determines  the  length 
of  time  and  ease  of  the  process  of  digestion  and  assimilation. 

The  finely  emulsified  fats  found  in  milk  and  eggs  may 
have  the  digestive  process  completed  in  the  stomach.  Those 
forming  a  different  emulsion  and  having  a  higher  melting- 
point  are  not  changed  until  they  reach  the  intestines  and 
come  in  contact  with  the  bile  salts  and  other  juices  which 
act  upon  the  fats. 

There  is  some  difference  of  opinion  as  to  the  extent 
of  the  influence  of  fats  in  the  process  of  the  digestion  of 
other  foods.  The  fact  that  fats  are  unaltered  in  the  mouth, 
except  for  being  melted  or  divided  into  fine  particles,  that 


FATS  AND  OILS  85 

only  certain  kinds  are  modified  in  the  stomach,  and  that 
others,  by  coating  the  mucous  Uning  of  the  stomach  with  a 
film  of  fat,  interfere  with  the  action  of  the  gastric  juice, 
leads  to  the  conclusion  that  a  meal  rich  in  fat  will  be  slow 
of  digestion.  Therefore,  in  summarizing,  it  may  be  said 
that  the  digestiblity  of  a  fat  depends  upon  its  melting- 
point  and  the  fineness  of  the  emulsion  in  which  it  occurs. 

145.  Sources  of  Fats. — Fats  are  obtained  from  both 
animal  and  vegetable  sources.  The  principal  animal  fats 
are  cream,  butter,  egg  yolk,  fat  of  beef,  mutton,  pork  and 
bacon,  bone  marrow,  chicken  fat,  and  cod  liver  oil. 

Vegetable  fats  are  those  derived  from  the  seeds  of  plants, 
as  olive  oil,  cottonseed  oil,  corn  oil,  and  nut  oils. 

Butter  and  cream  are  the  most  highly  prized  of  the 
animal  fats  because  of  the  ease  with  which  they  are  digested 
and  because  they  supply  important  vitamines,  fat-soluble 
substances.  They  are  expensive  foods  and  often,  where 
cost  must  be  considered,  it  is  necessary  to  substitute  some 
less  expensive  fat  for  ordinary  use.  Butterine  or  oleomar- 
garine may  be  used  in  place  of  butter,  except  for  table  use. 
Butter  contains  84  per  cent  of  fat,  about  12  per  cent  to  13 
per  cent  of  water,  a  little  curd,  and  nearly  2  per  cent  of 
salt. 

Butterine  and  oleomargarine  are  made  from  suet  and 
cottonseed  oil  churned  together  in  milk,  or  milk  and  cream, 
which  impart  a  small  amount  of  the  growth-stimulating 
substances  found  in  butter.  The  materials  used  and  the 
process  of  manufacture  are  usually  absolutely  clean  and 
wholesome  and  the  product  is  then  to  be  preferred  to 
renovated  butter  or  even  fresh  dairy  butter  made  under 
undesirable  conditions. 

Bacon  fat  ranks  with  butter  and  cream  in  the  matter 
of  expense  and  should  be  saved  and  utilized  in  the  cooking 
of  other  foods. 

Lard  is  the  fat  of  pork  rendered  and  refined.  The  best 
grade  is  called   leaf  lard,   and  is  extracted  from  the  soKd 


86  FOOD 

fatty  tissue  around  the  kidneys.  Other  grades  are  the 
rendered  fat  of  different  parts  of  the  animal. 

The  various  lard  substitutes  or  lard  compounds  sold 
under  such  trade  names  as  Crisco,  Snow  Drift,  etc.,  are 
chiefly  mixtures  of  beef  fat  and  cottonseed  oil. 

Beef  suet  is  the  hard,  kidney  fat  of  the  animal  and  is 
used  in  making  rich  puddings  and  mince  pies.  It  may  be 
melted  with  a  fat  of  a  lower  melting-point  to  form  a  medium 
fat  suitable  for  other  cooking  purposes. 

Mutton  fat  or  mutton  tallow,  on  account  of  its  strong  odor 
and  flavor,  is  not  combined  with  other  fats  for  household 
use. 

Bone  marrow,  the  fat  found  in  the  shin  bones  of  the 
beef  animal,  is  a  fat  of  low  melting-point  and,  consequently, 
is  easy  of  digestion.  It  gives  a  richness  and  flavor  to  soup 
stock  made  from  a  marrow  bone  which  is  not  found  in 
other  stock.  Its  chief  value,  however,  is  that  it  contains 
vitamines  having  a  remarkable  stimulating  influence  upon 
the  body. 

Chicken  fat  is  an  excellent  substitute  for  butter  in  cake 
making.  As  a  matter  of  fact,  it  may  be  used  for  any  purpose 
for  which  butter  is  used  except  on  bread. 

Cod  liver  oil  is  a  well  known  fat  recommended  as  a  body 
building  medicine,  and  probably  owes  its  beneficial  action 
to  the  presence  of  fat-soluble  substances  of  value  in  the 
building  and  repair  of  the  body  tissues. 

Olive  oil  is  manufactured  from  ripe  olives.  The  fruit 
is  gathered  just  before  it  turns  black,  because  at  this  stage 
it  contains  the  maximum  amount  of  oil.  To  obtain  the 
oil,  the  olives  are  first  crushed  and  the  oil  is  then  extracted 
by  pressure.  The  first  oil  that  flows  under  slight  pressure 
is  considered  of  superior  quality,  and  that  extracted  by 
greater  pressure  is  of  a  second  grade.  The  dark  color  is 
removed  by  allowing  the  oil  to  stand  until  the  sediment 
settles  and  then  filtering  it. 

The  flavor  of  olive  oil  is  dependent  upon  the  variety 


FATS  AND  OILS  87 

and  ripeness  of  the  olives  used  and  upon  the  temperature 
and  amount  of  pressure  used  at  the  time  it  is  obtained. 

Cottonseed  oil  is  used  in  combination  with  other  fats 
and  as  an  adulterant  of  and  substitute  for  olive  oil.  It  is 
undoubtedly  the  most  important  of  the  vegetable  fats 
now  in  use.  The  oil  which  is  extracted  from  the  seeds  by- 
pressure  is  refined  by  a  secret  process  which  removes  the 
characteristic  flavor.  The  cost  of  the  best  quality  of  cotton- 
seed oil  is  less  than  one-half  that  of  a  medium  grade  of 
olive  oil  and  the  value  is  essentially  the  same  since  both 
contain  practically  100  per  cent  of  .fat. 

Many  of  the  common  nuts  furnish  an  edible  nut  butter 
or  oil  of  low  melting-point,  which  is  much  valued  as  a  fuel 
food. 

146.  Cooking  in  Fats. — Fats,  when  heated  to  a  high 
temperature,  slowly  decompose,  giving  off  acrolein,  sl  sub- 
stance having  a  disagreeable  odor  and  an  irritating  effect 
upon  the  mucous  linings  of  the  body. 

Deep  fat  frying,  when  properly  done,  is  not  so  undesir- 
able as  formerly  believed  by  many  people.  If  the  fat  is 
not  heated  to  the  extreme  temperature  at  which  it  decom- 
poses so  that  the  food  does  not  carry  with  it  this  objectionable 
acrolein,  there  is  little  to  be  said  against  fried  food  for  the 
adult  having  a  normal  digestion.  It  is  the  abuse  of  this 
method  rather  than  its  use  that  should  be  condemned.  In 
selecting  a  medium  for  frying,  it  is  important  to  consider 
the  temperature  at  which  decomposition  takes  place.  Olive 
oil,  considered  by  many  people  as  the  best  medium  for  frying, 
may  be  heated  above  600°  F.  before  burning.  Crisco  and 
some  of  the  other  compounds  will  bear  much  more  heat  or 
about  800°  F.  Cottolene  has  a  burning  point  of  450°  F. 
and  lard  of  about  400°  F.  Butter  has  the  lowest  burning- 
point  or  about  350°  F.  and  is,  therefore,  not  desirable  as  a 
fat  for  frying. 

The  temperature  of  the  fat  suitable  for  this  method  of 
cooking  ranges  from  400°  F.  to  450°  F.  according  to  the 


88  FOOD 

nature  of  the  article  to  be  cooked.  A  piece  of  bread  one 
inch  square  will  turn  a  golden  brown  in  one  minute  in  a  fat 
that  is  at  the  right  temperature  for  frying  an  uncooked 
mixture  such  as  doughnuts  or  fritters,  and  in  forty  seconds 
when  the  fat  is  at  the  right  temperature  for  a  cooked  mixture 
such  as  croquettes.  Foods  likely  to  absorb  fat  during  this 
process  of  cooking  should  be  protected  by  a  covering  of  egg 
and  bread  crumbs.  The  egg  coagulates  readily  and  with 
the  crumbs  forms  a  crust  which  prevents  the  soaking  up 
of  fat  provided  the  temperature  of  the  fat  is  sufficiently  high. 

147.  Preparation  of  Fats. — Many  of  the  animal  fats  may 
be  utilized  in  combination  with  other  foods.  For  example, 
suet  drippings  and  other  hard  fats  may  be  tried  out,  clarified, 
and  mixed  with  cottonseed  oil  or  any  fat  having  a  low 
melting-point.  This  produces  a  mixture  having  a  medium 
melting-point  which  may  be  used  in  making  cakes  and  pastry. 
It  may  be  employed  also  as  a  medium  for  deep  fat  frying. 

At  this  time  when  great  stress  is  placed  upon  the  elimina- 
tion of  waste  in  the  household  the  use  of  fats  hitherto  unused 
is  extremely  important. 

148.  To  Clarify  Fat. — Fats  may  be  clarified  by  adding 
slices  of  raw  potato  to  the  fat  and  heating  slowly  until  it 
stops  foaming,  then  cooling  and  straining  through  a  cloth.  If 
the  fat  is  small  in  quantity,  add  a  considerable  amount  of 
boiling  water,  stir  vigorously,  and  allow  to  cool.  When  the 
fat  has  hardened,  remove  it  in  a  cake  from  the  top  of  the 
water.  A  sediment  will  be  found  on  the  bottom  of  the  cake 
of  .fat  which  may  be  removed  with  a  knife. 

149.  Rendering  Fats. — To  render  fat  remove  the  out- 
side skin  and  lean  from  fat  meat  and  cut  the  fat  in  small 
pieces.  Place  the  fat  in  a  kettle  and  cover  it  with  cold 
water.  Cook  slowly  in  an  uncovered  vessel  until  the  water 
is  all  evaporated,  then  reduce  the  heat  and  let  the  fat  slowly 
try  out.  When  the  fat  is  quiet  and  the  pieces  of  fatty 
tissue  are  settled  at  the  bottom  of  the  kettle,  cool,  strain 
through  a  cloth  and  allow  to  harden. 


FATS  AND  OILS  89 

EXPERIMENTS 

Experiment  1.  Solubility  of  Oil  in  Water. — Pour  a  teaspoonful 
of  oil  into  a  test  tube  and  add  the  same  quantity  of  water.  Shake 
well  and  then  examine.  Set  aside  for  a  while  and  examine  again.  Is 
oil  soluble  in  water? 

Experiment  2.  Spoon  Test  for  Butter. — Heat  a  piece  of  butter 
about  the  size  of  a  bean  in  a  tablespoon,  stirring  with  a  toothpick. 
Note  the  amount  of  foam  produced,  and  the  noise  made  in  boiling. 
Genuine  butter  makes  very  little  noise  on  boiling,  but  produces  much 
foam.  Renovated  butter  boils  noisily,  but  it  produces  little  foam, 
while  oleomargarine  boils  with  more  or  less  sputtering,  but  produces 
no  foam. 

SUGGESTIONS  FOR  LABORATORY  PRACTICE 

In  connection  with  the  study  of  the  text  of  the  preceding  chapter: 
Render  and  clarify  fats. 

Fry  in  deep  fat  croquettes,  fritters,  and  French  fried  potatoes. 
Prepare  salad  dressings:  French,  boiled  and  mayonnaise. 


CHAPTER  XI 
MILK 

150.  Value  As  Food.— Milk  contains  all  five  of  the 
foodstuffs  and  on  this  account  is  sometimes  spoken  of  as  a 
perfect  food.  It  is  a  perfect  food  only  for  an  infant,  for 
while  it  contains  all  of  the  nutrients  required  by  the  body, 
these  are  not  in  the  right  proportion  for  the  nourishment 
of  an  adult.  Owing  to  the  large  percentage  of  water  which 
it  contains,  it  is  too  bulky;  to  get  the  proper  amount  of 
other  nutrients  a  man  would  have  to  consume  at  least  eight 
pints  a  day. 

TABLE  VII.— AVERAGE  COMPOSITION  OF   MILK 

Protein 3.3% 

Fat 4.0% 

Carbohydrates 5.0% 

Mineral  matter 0 . 7% 

Water 87.0% 

Milk  in  normal  times  is  one  of  the  cheapest  sources  of 
animal  protein;  the  amount  of  protein  in  one  quart  of  milk 
being  equal  to  that  in  one  pound  of  beef  or  in  eight  or  nine 
eggs.  Milk  depends  largely  for  its  fuel  value  on  the  amount 
of  fat  present.  Milk  with  only  four  per  cent  of  fat  will 
yield  675  calories  per  quart;  from  97  to  98  per  cent  of  milk 
protein  is  said  to  be  absorbed.  The  fact  that  milk  has  no 
waste  and  may  be  used  without  preparation  should  make  it 
a  very  valuable  part  of  the  diet.  That  it  is  a  tissue  building 
and  growth  producing  food  makes  it  especially  valuable 
in  the  feeding  of  children. 

151.  Composition. — Milk  varies  greatly  in  composition; 
much  depends  upon  the  breed,  age,  and  food  of  the  cow. 

90 


MILK 


91 


The  amount  of  fat  present  is  a  good  indication  of  the  quaUty 
for  milk  rich  in  cream  is  always  found  to  be  correspondingly 
rich  in  protein  and  sugar.  Usually  the  amount  of  fat  sets 
the  price  standard  commercially,  and  most  states  require 
milk  to  contain  4  per  cent  of  fat. 

Protein  in  milk  is  represented  by  casein  and  albumin. 
The  casein  is  different  from  the  albumin  in  that  it  contains 
phosphorus  and  sulphur.  Casein  is  coagulated  by  acid  and 
rennet.  The  action  of  acid  is  called  ''curdling,"  and  that 
of  rennet,  ''clotting."  In  curdling,  the  casein  is  simply 
precipitated  without  undergoing  any  chemical  change ;  this 
is  supposed  to  be  due  to  the  fact  that  acid  separates  the 
lime  salts  from  the  casein,  and  then  it  becomes  insoluble. 

TABLE  VIII.— COMPARATIVE    FOOD  VALL^  OF  MILK  AND 
THE   EDIBLE   PORTION   OF  OTHER   COMMON   FOODS 


Refuse. 

Water. 

Pro- 
tein. 

Fat. 

Carbo- 
hydr- 
ates. 

Miner- 
als. 

Food 

Value, 

Calories. 

Whole  milk,  1  lb. . 

0.00 

0.87 

0.03 

0.04 

0.05 

0.01 

325 

Skim  milk,  1  lb. .  . 

0.00 

0.90 

0.04 

0.05 

0.01 

170 

Cheese,  lib 

0.00 

0.34 

0.26 

0.34 

0.04 

1965 

Butter,  1  lb 

0.00 

0.11 

0.01 

0.85 

0.03 

3605 

Baef  (round),  1  lb. 

0.08 

0.61 

0.18 

0.12 

0.01 

870 

Pork  (ham),  1  lb. . 

0.14 

0.35 

0.13 

0.34 

0.04 

1655 

Wheat  bread,  1  lb. 

0.00 

0.35 

0.10 

0.01 

0.53 

0.01 

1205 

Oatmeal,  1  lb 

0.00 

0.07 

0.16 

0.07 

0.68 

0.02 

1860 

Dried  beans,  1  lb . 

0.00 

0.13 

0.22 

0.02 

0.59 

0.04 

1590 

Potatoes,  1  lb. .  .  . 

0.15 

0.67 

0.02 

0.15 

0.01 

325 

Albumin  is  present  in  very  small  quantities  and  is  coagu- 
lated very  slowly  when  milk  is  heated. 

Fat  is  represented  by  cream  which  is  distributed  through 
the  fresh  milk  in  the  form  of  globules,  but  these,  being 
lighter  than  water,  rise  to  the  surface  as  the  milk  stands. 
Commercially  speaking,  fat  is  the  most  important  constituent 
of  the  milk  as  from  it  butter  is  made. 


92  FOOD 

Carbohydrate  is  represented  in  milk  by  the  milk  sugar 
or  lactose;  this  is  somewhat  different  from  cane  sugar, 
as  it  is  not  so  sweet  and  does  not  easily  ferment.  It  is 
affected  by  certain  bacteria  that  split  it  and  produce  lactic 
acid. 

Mineral  matter  is  represented  by  phosphorus  and  calcium 
compounds  in  relatively  large  quantities,  and  a  small  amount 
of  iron. 

152.  Digestibility. — When  milk  enters  the  stomach,  it 
clots  through  the  action  of  the  rennin  present  in  the  stomach. 
That  it  is  not  curdled  through  the  action  of  the  gastric 
juice,  which  is  acid,  is  probably  due  to  the  fact  that  the 
alkaline  salts  of  the  milk  neutralize  the  acid  first,  and  so 
gives  the  rennin  time  in  which  to  act.  This  clot  in  some 
cases  becomes  very  tough  and  leathery,  and  on  this  account 
many  people  find  milk  difficult  of  digestion.  The  addition 
of  lime  water  or  an  aerated  w^ater  to  the  milk  is  said  to  be 
efficacious  in  preventing  the  formation  of  this  tough  curd. 
If  for  any  reason  milk  is  not  digested  in  the  stomach,  it  is 
found  to  be  readily  digested  in  the  small  intestine.  Milk 
is  constipating  when  used  alone,  because  the  residue  left 
from  it  is  not  sufficiently  bulky  to  produce  peristalsis. 
Milk  does  not  yield  uric  acid  in  the  body  or  produce  intes- 
tinal putrefaction. 

153.  The  Care  of  Milk. — The  greatest  care  should  be 
exercised  in  handling  milk;  absolute  cleanliness  and  a  low 
temperature  are  essential,  because  milk  furnishes  one  of  the 
best  mediums  for  the  growth  of  bacteria.  A  temperature 
of  50  degrees  is  desirable.  Milk  should  be  bottled  at  the 
place  of  production  and  kept  in  contact  with  ice  until  it 
reaches  the  consumer.  Old  milk  should  never  be  mixed 
with  new,  and  if  kept  at  50  degrees  should  remain  sweet 
at  least  twelve  hours. 

154.  Skim  Milk. — Milk  from  which  the  fat  or  cream 
has  been  removed  is  called  skim  milk.  The  amount  of  fat 
which  remains  depends  upon  the  method  of  creaming.     With 


MILK  93 

the  exception  of  fat,  skim  milk  contains  all  the  constituents 
of  whole  milk,  and  may  be  used  advantageously. 

155.  Sour  Milk. — When  milk  stands  too  long  or  in  a 
warm  place,  the  bacteria  in  it  rapidly  multiply  and  change 
the  sugar,  or  lactose,  into  an-  acid  called  lactic  acid.  This 
acid  acts  on  the  casein,  hardening  it  and  giving  to  spur  milk 
its  characteristic  curdled  appearance.  As  the  greater  por- 
tion of  lactic  acid  is  formed  during  the  first  twenty-four 
hours  and  the  process  is  generally  completed  in  forty-eight 
hours,  it  follows  that  sour  milk  should  be  made  use  of  without 
further  delay. 

156.  Certified  Milk. — Certified  milk  is  milk  that  has 
been  produced  under  the  very  best  sanitary  conditions 
and  under  the  supervision  of  a  medical  milk  commission. 
Its  cost  is  about  twice  that  of  ordinary  milk  because  of  the 
extra  expense  in  producing  it.  It  forms  less  than  one  per 
cent  of  the  milk  of  commerce. 

157.  Pasteurized  Milk. — Pasteurized  milk  is  milk  that 
has  been  heated  to  a  temperature  of  140°  F.  or  145°  F.,  kept 
at  this  temperature  twenty  to  thirty  minutes,  and  then 
cooled  rapidly.  This  process  does  not  kill  all  bacteria,  but 
is  supposed  to  destroy  bacteria  of  diseases  transmissible 
by  milk,  such  as  tuberculosis,  typhoid  fever,  etc. 

158.  Sterilized  Milk. — This  is  milk  that  has  been  raised 
to  a  temperature  sufficiently  high  to  kill  all  active  bacteria 
present.  In  the  light  of  the  latest  scientific  investigations 
there  is  no  difference  in  the  nutritive  value  of  boiled  and 
unboiled  milk. 

159.  Condensed  Milk. — Milk  from  which  a  large  pro- 
portion of  the  water  has  been  evaporated  is  known  as  con- 
densed milk.  The  unsweetened  or  commonly  called  ''evap- 
orated" milk  has  a  creamy  consistency,  is  sold  in  bottles, 
and  must  be  used  within  a  few  days.  The  sweetened  has  a 
large  amount  of  cane  sugar,  40  per  cent,  and  being  sealed 
in  tin  cans  may  be  kept  indefinitely. 

160.  Milk  Powder. — By  milk  powder  is  meant  milk  that 


94  FOOD 

has  been  evaporated  to  a  fine  white  powder.  When  water 
is  added,  the  product  resembles  ordinary  milk  and  may 
be  used  in  cooking. 

161.  Modified  Milk. — Modified  milk  is  cow's  milk  which 
is  designed  to  replace  mother's  milk  in  the  feeding  of  infants. 
As  the  proportion  of  the  foodstuffs  differ  in  the  two  milks, 
the  cow's  milk  containing  more  protein  and  less  sugar  than 
human  milk,  this  difference  is  remedied  by  adding  to  the 
cow's  milk  lactose,  or  some  digestible  carbohydrates  such 
as  rice  flour  or  arrowroot,  and  a  certain  amount  of  sterile 
water.  The  casein  of  cow's  milk  is  harder  to  digest  on 
account  of  the  toughness  of  the  curd  formed. 

The  custom  of  adding  lime  water  to  milk  with  the  mis- 
taken idea  of  increasing  the  alkalinity  of  the  milk  no  longer 
holds  good,  as  it  has  been  found  that  lime  water  decreases 
rather  than  increases  this  alkalinity,  because  of  the  pre- 
cipitation of  the  calcium  phosphate. 

162.  Malted  Milk. — Malted  milk  is  a  mixture  of  des- 
iccated milk,  wheat  flour,  barley  malt,  and  bicarbonate  of 
soda.  This  milk  is  sometimes  found  to  be  more  easy  of 
digestion  than  ordinary  milk;  this  is  due  to  the  fact  that  the 
casein,  like  that  of  condensed  milk,  clots  very  loosely  or 
not  at  all. 

163.  Milk  in  Cooking. — The  addition  of  milk  to  any 
recipe  greatly  increases  the  nutritive  value.  Bread  made 
with  milk  is  much  higher  in  food  value  than  that  made 
with  water.  Milk  soups  are  a  great  source  of  nitrogenous 
material  in  a  diet.  White  sauces  are  not  only  useful  nutri- 
tively but  economically  in  utilizing  left  over  food.  Simple 
desserts  made  principally  of  milk  are  highly  recommended 
dietetically. 

164.  Butter. — Butter  is  made  from  the  cream  of  milk. 
The  practice  of  pasteurizing  the  cream  before  churning  is 
to  be  recommended,  not  only  to  eliminate  all  danger  of 
disease,  but  to  get  rid  of  the  bacteria  present  so  that  bacteria 
that  will  produce  only  the  desired  acid  fermentation  may 


MILK       •         *  95 

be  added.     The  pleasant  flavor  and  aroma  of  butter  is  due 
to  this  fermentation. 

TABLE  IX.— COMPOSITION  OF  BUTTER 

Fat 84.0% 

Casein 1.30% 

Moisture 12.73% 

Salts. 1.97% 

Butter  is  one  of  the  most  easily  digested  and  absorbed 
forms  of  fat.  This  may  be  due  to  the  fact  that  the  butter 
fat  is  about  40  per  cent  olein,  a  substance  which  enters 
largely  into  the  composition  of  body  fat;  also  because  of 
its  low  melting-point. 

Butter  is  the  greatest  source  of  fat  in  the  diet  of  most 
people  and  is  especially  valuable  in  the  treatment  of  such 
diseases  as  phthisis, 'diabetes,  etc. 

165.  Butter  Substitutes. — Butter  which  has  stood  so 
long  that  it  has  become  rancid  may  be  melted  to  get  rid 
of  the  disagreeable  odor  and  flavor  and  then  rechurned 
with  fresh  milk  or  cream.  The  product  is  known  as  renovated 
butter. 

Oleomargarine  is  made  by  churning  fat  together  with 
milk  or  milk  and  cream. 

166.  Cheese. — Cheese  is  made  from  the  curd  of  milk 
which  undergoes  processes  of  ''ripening,"  coagulating, 
removing  whey,  salting  and  pressing. 

Cheese  may  be  divided  into  two  classes: 

1.  Hard:  Chedder,  Edam,  Swiss,  Parmesan,  Roquefort. 

2.  Soft:  Brie,  Camembert,  Gorgonzola,  Lim.burger, 
Neufchatel,  Stilton. 

Contrary  to  popular  opinion,  cheese  is  not  difficult  of 
digestion  if  eaten  at  the  proper  time  and  in  suitable  amounts. 
Recent  experiments  show  that  95  per  cent  of  the  protein 
and  more  than  95  per  cent  of  the  fat  is  digested  and  absorbed. 
Cheese,  like  milk,  is  digested  chiefly  in  the  intestines. 

Food  value. — As  cheese  is  deficient  in  carbohydrates,  its 


96  FOOD 

food  value  is  greatly  increased  by  serving  it  with  carbo- 
hydrate foods  such  as  bread,  rice,  etc.  As  it  is  a  highly 
concentrated  food  it  is  well  to  use  it  in  combination  with  such 
bulky  foods  as  vegetables.  As  it  is  practically  the  same 
type  of  food  as  meat,  fish,  and  eggs,  it  should  be  used  to 
replace  these  articles  in  a  meal,  not  to  supplement  them. 
If  not  used  in  too  large  quantities,  cheese  will  be  found 
useful  in  a  diet. 

SUGGESTIONS  FOR  LABORATORY  PRACTICE 

In  connection  with  the  study  of  the  text  of  the  preceding  chapter: 
Make  butter,  cottage  cheese,  junket,  cocoa,  and  cream  soups. 


CHAPTER  XII 
EGGS 

167.  Structure. — Structurally  the  egg  is  divided  as 
follows : 

Shell. — Composed  largely  of  lime  and  magnesium  salts. 
White. — Composed    of  water,    protein,   ash,    and    small 
amount  of  fat. 

Yolk. — Composed  of  water,  protein,  fat,  and  ash. 
Membranes. — (1)  The  tough  skin  covering  the  whole  of 
the  egg  under  the  shell. 
(2)  The  delicate  tissue  surrounding  the  yolk. 

168.  Composition. — Eggs,  like  milk,  contain  a  large  per- 
centage of  water  and  an  important  amount  of  protein,  fat 
and  mineral  salts,  but  no  starch. 

The  average  composition  of  egg  as  purchased  is  water 
65.5  per  cent;  protein  11.9  per  cent;  fat  9.3  per  cent;  and 
mineral  matter  0.9  per  cent. 

The  protein  of  egg  is  albumin  which  is  a  valuable  tissue 
building  food.  White  of  egg  consists  of  several  albumins, 
the  chief  of  which  is  ovalbumin.  Popularly,  egg  white  is 
called  pure  albumin.  Egg  yolk  also  contains  a  number  of 
different  proteins,  including  a  large  percentage  of  vitellin 
and  lecithin  which  furnish  phosphorus  in  a  form  available 
for  the  body  needs. 

The  fat  of  egg  is  found  chiefly  in  the  yolk,  and,  like 
milk  fat,  exists  as  an  emulsion.  Held  in  solution  in  the 
fat  of  the  egg  yolk  is  found  a  vitamine  ( fat  soluble  A  is  the 
name  given  to  this  substance  by  scientists),  which  is  essential 
for  the  best  growth  and  development  of  the  body.  A 
yellow  coloring  matter  called  lutein  is  dissolved  in  the  fat 

97 


98  FOOD 

of  the  yolk  and  gives  it  the  characteristic  color.  This  color- 
ing depends  somewhat  upon  the  nature  of  the  food  of  the 
hens.  Pale-colored  yolks  are  thought  to  indicate  a  deficiency 
in  green  food. 

The  chief  ash  constituents  of  the  egg  are  phosphorus, 
calcium,  iron,  and  sulphur.  The  yolk  of  the  egg  is  much 
richer  than  the  white  in  these  compounds,  which  are  adapted 
to  an  important  part  in  the  building  of  blood,  bone,  and 
muscle.  The  edible  portion  of  an  egg  shows  an  average 
of  0.0030  per  cent  of  iron  in  forms  available  for  use  in  the 
body.  The  richness  of  the  egg  in  iron  compounds  is  one  of 
the  reasons  for  the  early  addition  of  egg  to  the  diet  of  a 
young  child. 

The  high  sulphur  content  of  egg,  found  chiefly  in  the 
albumin  of  the  white,  results  in  an  excess  of  acid  forming 
elements  and  makes  the  egg  an  acid-forming  food.  In  this 
particular,  egg  resembles  meat  rather  than  milk.  The 
sulphur  present  forms  hydrogen  sulphide  on  the  decomposi- 
tion of  the  albumin,  giving  the  bad  odor  to  rotten  eggs. 

169.  Food  Value. — An  egg  of  average  size  will  yield 
about  75  calories.  An  egg  weighing  two  and  two-third 
ounces  will  yield  100  calories.  One  pound  of  egg  (eight 
eggs  of  average  size)  will  yield  672  calories  or  twice  as 
much  as  are  furnished  by  an  equal  weight  of  milk  and 
a  little  less  than  the  calories  from  a  pound  of  lean  meat. 
This  indicates  that  eggs  at  ordinary  prices  are  an  economical 
substitute  for  meat.  The  exceptional  nature  and*  high 
food  value  of  the  nutrients  of  egg  places  it  among  the  indis- 
pensable articles  of  diet  in  every  household  and  gives  it  a 
prominent  place  in  the  dietary  of  anaemic  and  tubercular 
patients. 

170.  Digestibility. — Egg  protein  or  albumin  is  digested 
and  absorbed  as  completely  as  milk  protein  or  case  in  (97-98 
per  cent  absoibed),  and  the  fat  of  eggs  is  digested  as  thor- 
oughly as  milk  fat.  Experiments  have  shown  that  eggs 
slightly  cooked  at  a  temperature  below  that  of  boiling  water, 


EGGS  99 

are  more  easily  and  quickly  digested  than  those  cooked  at 
a  higher  temperature.  Moderate  heat  makes  the  albumin 
tender  and  jelly-like,  while  strong  heat  makes  it  tough, 
hard,  and  dry,  in  which  condition  it  offers  more  resistance 
to  the  digestive  juices. 

171.  Selection  and  Care. — Eggs  are  divided  commercially 
into  groups  according  to  freshness,  appearance,  size,  cleanli- 
ness, and  color. 

In  absolutely  fresh  eggs,  the  contents  very  nearly  fill 
the  shell  and  the  white  is  jelly-like  in  consistency  and  is 
practically  free  from  bacteria.  As  soon  as  an  egg  is  laid, 
the  water  begins  to  evaporate  through  the  porous  shell, 
gradually  increasing  the  size  of  the  air  space  inside  the  shell. 
As  the  evaporation  continues,  this  space  is  being  filled  with 
micro-organisms  which  set  up  fermentation  and  cause  the 
egg  to  spoil. 

Freshness  is  determined  in  various  ways.  Candling 
and  the  salt  solution  tests  are  most  frequently  employed 
where  large  numbers  of  eggs  are  to  be  examined.  Shaking 
to  determine  the  fullness  of  the  shell,  and  observing  the 
roughness  of  the  shell  are  the  simplest  of  the  household  tests. 

Candling  consists  in  looking  through  the  egg  toward  a 
bright  light  and  noting  the  appearance  of  the  contents.  A 
perfectly  fresh  egg  appears  unclouded  or  translucent,  as 
is  shown  at  A  in  Fig.  27.  If  decomposition  has  begun,  a 
dark  spot  may  be  observed  which  gradually  increases  in 
size  as  shown  in  B  and  C.  A  bad  egg  or  one  unfit  for  use 
appears  dai'k  colored  all  over  as  in  D. 

Crack  shelled  eggs  are  easily  inoculated  with  bacteria  cr 
contaminated  by  odors  and  can  be  kept  for  only  a  short 
time.  They  are  sold  much  cheaper  and  may  be  used  when 
it  is  certain  that  they  are  fresh  and  clean. 

Dirty  shell  eggs  are  undesirable  because  they  have  been 
in  contact  with  filth  and  are  liable  to  be  contaminated. 
Seconds  are  the  undersize,  cracked,  or  soiled  eggs,  or  those 
otherwise  unfitted  to  be  classed  as  first  grade. 


100 


FOOD 


Courtesy  of  The  Macmillan  Co. 

Fig.  27. — Appearance  of  different  grades  of  eggs  before  the  candle. 


EGGS  101 

The  color  of  the  egg-shell  influences  somewhat  the  mar- 
ket value  but  not  the  food  value.  Analysis  shows  that  there 
is  no  uniform  difference  in  the  properties  and  food  value  of 
brown-shelled  and  white-shelled  eggs.  Brown-shelled  eggs 
bring  the  higher  price  in  the  Boston  markets,  while  white- 
shelled  eggs  are  preferred  in  the  New  York  markets. 

172.  Specific  Gravity. — At  the  New  York  State  Experi- 
ment Station  it  was  found  that  the  average  fresh  egg  has  a 
specific  gravity  of  1.090.  The  changes  in  specific  gravity 
correspond  to  the  changes  in  water  content.  As  the  egg 
becomes  older  its  density  increases  through  the  evaporation 
of  water  through  the  pores  of  the  shell. 

173.  Preservation. — A  large  percentage  of  the  eggs  used 
are  produced  hundreds  of  miles  from  the  consumer,  thus 
necessitating  safe  methods  of  transporation  and  preservation. 
Eggs  designed  for  shipping  long  distances  should  be  perfectly 
fresh.  They  should  be  carefully  packed  in  special  cases  to 
insure  freedom  from  contact  with  materials  having  strong 
or  unpleasant  odors.  Eggs  are  most  plentiful  and  cheapest 
during  April,  May,  and  June,  and  should  then  be  stored 
for  use  in  the  winter  months. 

The  methods  of  preserving  eggs  may  be  grouped  under 
three  general  classes : 

(1)  By  preventing  contact  with  the  air,  by  immersing 
the  eggs  in  a  solution  of  some  sort. 

(2)  By  keeping  them  at  a  low  temperature,  as  in  cold 
storage  or  freezing. 

(3)  By  evaporating  the  moisture  as  in  drying. 

For  the  individual  housekeeper,  preventing  contact  with 
the  air  is  probably  the  most  satisfactory.  To  accomplish 
this. pack  the  eggs  in  a  suitable  container  and  pour  over 
them  a  10  per  cent  solution  of  water-glass  (sodium  silicate) 
until  the  eggs  are  completely  covered.  It  is  claimed  that 
this  method  will  keep  the  eggs  in  a  wholesome  condition 
from  four  to  six  months  and  retain  to  a  surprising  degree 
the  flavor  and  appearance  of  freshness.     Packing  in  salt, 


102  FOOD 

bran,  or  sawdust,  little  end  down,  has  been  found  an  adequate 
means  of  preserving  eggs  for  cooking  purposes  by  many- 
housekeepers.  The  object  in  all  these  methods  is,  of  course, 
to  fill  the  pores  of  the  shell  and  prevent  the  evaporation 
of  the  contents. 

When  fresh  eggs  are  put  in  cold  storage,  at  a  temperature 
of  32°  to  34°  F.,  they  keep  for  several  months  with  but 
slight  change  in  quality  and  flavor.  Eggs  should  be  candled 
after  removing  from  cold  storage.  It  is  advisable  to  use 
storage  eggs  soon  after  they  are  taken  from  storage,  as  they 
deteriorate  rapidly  after  changing  the  temperature  con- 
ditions. Sometimes  eggs  are  broken  and  sold  in  the  bulk. 
This  necessitates  freezing  and  keeping  at  a  temperature  of 
30°  F.,  or  a  little  below  freezing-point. 

Broken  eggs  are  often  dried  or  desiccated.  The  product 
is  usually  ground  into  a  powder.  This  powder  is  thoroughly 
mixed  with  water  and  used  in  place  of  fresh  eggs. 

A  number  of  egg  substitutes  are  on  the  market.  They 
are  usually  a  compound  of  corn  starch  and  casein  and  do 
not  really  take  the  place  of  eggs  because  they  do  not  furnish 
the  nutrients  which  give  the  egg  its  prominent  place  as  a 
food  material. 

174.  Preparation  and  Cooking. — Eggs  may  be  cooked 
in  a  variety  of  ways.  In  the  shell,  as  soft  cooked  or  hard 
cooked;  broken  and  left  whole,  as  baked  or  poached;  beaten, 
as  in  omelet  or  scrambled  egg;  or  in  combination  with  other 
materials,  as  in  puddings,  custards,  cakes  and  sauces.  In 
all  cases  the  effect  of  heat  upon  albumin  should  be  kept  in 
mind.  When  the  white  of  egg  is  heated  to  a  temperature  of 
134°  F.,  it  slowly  changes  to  a  semi-transparent  mass.  When 
heated  to  160°  F.,  it  is  coagulated  or  becomes  opaque  and 
more  or  less  solid.  The  yolk  of  egg  coagulates  at  a  some- 
what lower  temperature  than  the  white,  or  about  122°  F. 

Custards  should  be  poached  or  baked  in  a  pan  of  water 
which  is  not  allowed  to  reach  the  boiling-point,  in  order 
to  insure  a  smooth,  jelly-like  mass. 


EGGS  103 

The  coagulation  of  albumin  is  demonstrated  in  the  use 
of  egg  for  clearing  coffee.  As  the  coagulated  albumin 
rises  to  the  surface  it  carries  with  it  the  scattered  grounds 
and  clears  the  coffee. 

EXPERIMENTS 

Experiment  1.  The  Effect  of  Heat  upon  Albumin. — (1)  Place  the 
white  of  an  egg  in  a  beaker  and  heat  gradually  in  a  saucepan  of 
water.  Test  with  a  thermometer  and  note:  (a)  the  temperature  at 
which  it  begins  to  harden;  (6)  the  temperature  at  which  the  egg  is 
completely  hardened. 

(2)  Examine  and  compare  the  coagulated  albumin  in  the  beaker 
in  (1)  with  an  equal  amount  of  egg  white  that  has  been  boiled  five 
minutes.  Draw  conclusions  as  to  the  temperature  at  which  albumin 
should  be  cooked  to  make  it  tender  and  easily  digested. 

Experiment  2.  Comparison  of  Lightness  of  Egg  Beaten  with  a 
Dover  Beater  and  with  a  Swedish  Beater. — (a)  Beat  the  white  of  an 
egg  with  a  Dover  Beater  and  measure  the  product  in  a  standard  meas- 
uring cup. 

(6)  Beat  another  egg  with  a  Swedish  beater. 

Compare  (a)  and  (6)  as  to  quantity  and  as  to  the  size  of  the  air 
cells. 

SUGGESTIONS  FOR  LABORATORY  PRACTICE 

In  connection  with  the  study  of  the  text  of  the  preceding  chapter 
prepare : 

Eggs:  soft  and  hard  cooked,  poached,  scrambled,  and  omelets. 
Boiled  and  baked  custards. 


CHAPTER  XIII 
MEATS 

175.  Structure. — ^Meat,  which  is  the  flesh  of  animals 
used  for  food,  is  made  up  of  the  lean  or  muscular  tissue, 
fatty  tissue,  gristle,  and  bone. 

If  a  piece  of  lean  meat  be  examined  under  the  micro- 
scope, it  will  be  found  to  consist  of  fiber  held  together  in 
bundles  by  a  thin  membrane  which  is  the  connective  tissue. 
On  closer  examination  these  fibers  are  seen  to  be  hollow 
tubes  filled  with  a  liquid  which  is  called  muscle  juice. 

176.  Kinds. — Meat  may  be  either  tender  or  tough. 
Both  kinds  may  come  from  the  same  animal,  but  from 
different  parts  of  the  creature. 

Tender  meat  comes  from  the  muscles  of  the  animal  that 
are  used  but  little.  There  is  a  minimum  amount  of  con- 
nective tissue  in  tender  meat,  and  it  is  delicate  and  easily 
broken.     The  tube  walls  are  also  delicate. 

Tough  meat  comes  from  the  muscles  of  the  animal  that 
are  used  a  great  deal.  The  fibers  are  coarse  and  the  con- 
nective tissue  thick  and  hard. 

177.  Ripening. — The  process  known  as  ripening  has  much 
to  do  with  the  texture  of  meat.  Immediately  after  slaughter- 
ing, the  meat  is  juicy  and  tender,  but  shortly  afterwards  a 
stiffening  of  the  muscles  takes  place,  probably  because  the 
myosin  of  the  muscle  juice  clots.  The  meat  must  then  be 
allowed  to  hang  or  ripen,  during  which  time  an  acid  is  formed. 
This  acid  not  only  acts  as  a  solvent  upon  the  coagulated 
myosin,  but  also  imparts  a  pleasant  flavor  to  the  meat. 

178.  Composition. — Meat  contains: 

1.  Proteins   such    as,    albumin,    myosin,    collagen,    and 

104 


MEATS  105 

elastin,    and    also    gelatin,    which    closely    resembles    true 
protein. 

2.  Fat  in  varying  amounts  from  3  per  cent  as  in  dried 
beef,  to  90  per  cent  in  fat  pork. 

3.  Carbohydrates,  less  than  1  per  cent  and  in  the  form  of 
glycogen  or  muscle  sugar. 

4.  Mineral  matter  in  the  form  of  potash,  lime,  magnesia, 
iron,  etc. 

5.  Water  varying  from  50  to  75  per  cent. 

179.  Digestibility. — Meat  contains  the  most  easily  and 
quickly  digested  forms  of  proteins,  98  per  cent  of  which  is 
digested  and  absorbed.  Fat  is  digested  according  to  the 
amount  eaten,  large  quantities  retarding  digestion.  The 
extractives,  which  are  the  substances  which  give  to  the 
different  meats  their  characteristic  flavors,  also  aid  digestion 
by  stimulating  the  flow  of  gastric  juice. 

180.  Food  Value. — Because  of  the  high  protein  content 
of  meat  and  the  ease  with  which  it  is  digested,  meat  has  a 
high  food  value.  Too  much  meat,  however,  may  be  harm- 
ful, probably  owing  to  the  fact  that  the  decomposition 
products  are  difficult  to  eliminate  from  the  body.  The 
uric  acid  forming  substances  are  abundant,  and  meat  pro- 
tein is  very  susceptible  to  intestinal  putrefaction.  The 
fuel  value  of  meat  depends  to  a  great  extent  on  the 
amount  of  fat  eaten. 

181.  Selecting  Meats. — All  meat  should  come  from 
healthy,  well-fed  animals,  and  should  be  free  from  dyes, 
chemicals  or  preservatives  that  in  any  way  render  it  unfit 
for  food.  In  choosing  meat  such  points  as  color,  texture, 
amount  of  fat,  etc.,  will  differ  with  the  different  kinds  of 
meat,  but  general  points  to  observe  are  freshness,  soundness, 
and  absence  of  odor. 

182.  Cooking. — The  way  in  which  meat  should  be  cooked 
depends  upon  whether  it  is  tough  or  tender.  The  object 
of  all  cooking  is  to  kill  parasites  and  bacteria,  to  improve 
the  flavor  and  appearance  of  the  meat,  and  to  loosen  the 


106  FOOD 

fibers  so  that  they  may  be  more  readily  acted  upon  by  the 
digestive  juices.  Tender  meat  should  be  so  cooked  as  to 
retain  the  juices.  This  is  accomplished  by  applying  a 
high  degree  of  heat  at  first.  This  sears  the  surface  of  the 
meat  by  coagulating  the  albumin,  thus  preventing  the 
evaporation  of  the  juices. 

Tough  meat  should  be  so  cooked  as  to  soften  the  con- 
nective tissue  and  change  it  into  gelatin.  This  is  best 
accomplished  by  cooking  in  water  below  the  boiling-point 
for  a  long  time. 

183.  Methods  cf  Preserving  Meat. — Meat  may  be  pre- 
served by  refrigeration,  freezing,  drying,  canning,  pickling, 
smoking,  and  the  use  of  such  preservatives  as  salt,  sugar, 
vinegar,  and  saltpeter.  Meat  that  is  to  be  sold  as  fresh  is 
kept  in  such  condition,  for  a  certain  length  of  time,  by 
simply  hanging  in  the  ordinary  cold  storage  room.  Certain 
states  have  laws  governing  the  length  of  tim.e  the  meat 
may  be  kept. 

If  meat  is  to  be  kept  a  very  long  time,  it  must  be  frozen — 
that  is,  none  of  the  juices  may  remain  liquid,  and  the  fibers 
must  be  separated  by  layers  of  ice.  This  condition  may  be 
brought  about  by  subjecting  the  meat  to  a  temperature  of 
about  15°  F.  Frozen  meat  should  be  thawed  very  slowly 
before  cooking,  otherwise  it  will  be  flabby. 

184.  Beef. — Beef  is  more  extensively  used  than  any 
other  kind  of  meat.  Farm  cattle  are  supposed  to  give  a 
higher  grade  of  beef  than  ranch  cattle.  Good  beef  has  the 
following  characteristics: 

(1)  The  color  is  bluish  red. 

(2)  The  flesh  is  firm  and  elastic,  scarcely  moistening 
the  finger  when  touched. 

(3)  It  is  almost  odorless. 

(4)  In  the  more  expensive  cuts,  the  fibers  are  fine  with 
very  little  connective  tissue. 

(5)  The  lean  part  is  well  marbled  with  fat. 

(6)  The  fat  is  firm,  clear,  and  free  from  spots. 


MEATS 


107 


1.  Neck. 

2.  Chuck. 

3.  Kibs. 

4.  Shoulder  clod. 

5.  Fore  shank. 

6.  Brisket. 

7.  Cross   ribs, 

8.  Plate. 

9.  Navel. 

10.  Loin. 

11.  Flank. 

12.  liump. 

13.  Rpund. 

14.  Second  cut  round, 
15'.   Ilind  shank. 


Fig.  28. — Diagrams  of  cuts  of  beef. 


108 


FOOD 


(7)  An  acid  reaction  is  given  to  litmus  paper.  An 
alkaline  or  neutral  reaction  indicates  that  some  preservative 
has  been  used. 

185.  Cuts  of  Beef. —(See  Fig.  28.) 


(a)  Fore  Quarter 

Part 

Uses 

1.  Neck 

Beef  tea 

2.   Chuck 

Steaks  and  Roasts 

3.   Ribs,  5th  and  6th 

Roasts 

4.   Shoulder 

Pot  Roasts 

5.  Fore  shank 

Soup 

6.  Brisket 

Corning 

7.  Cross  ribs 

Pot  roast 

8.  Plate 

Stewing  and  corning 

9.  Navel 

Stewing  and  corning 

< 

(6)  Hind  Quarter 

Part 

Uses 

10.  Loin 

Steaks  and  roasts 

11.  Flank 

Steak  and  corning 

12.  Rump 

Steak,  roasts,  corning 

13.  Round 

Steaks,  Beef  a  la  Mode 

14.  Second  cut  of  round 

Pot  roast  and  corning 

15.  Hind  shank 

Soups 

186.  Veal.— Veal 

is  the 

flesh  of  the  calf.     Good  veal 

mes  from  an  animal  about  two  months  old.     The  color 

should  be  dull  pink. 

A  recent  investigation  as  to  the  comparative  food  value 
of  immature  veal  and  mature  beef,  has  brought  to  light  the 
fact  that  the  difference  in  composition  between  the  two 
is  so  slight  as  to  be  of  no  physiological  significance.  How- 
ever, the  larger  proportion  of  connective  tissue  found  in  the 
veal  makes  it  necessary  to  cook  veal  slowly  for  a  long  time 
so  that  this  connective  tissue  may  be  softened.     When  this 


MEATS 


109 


is  done  the  veal  has  been  found  to  be  quite  as  easily  digested, 
and  as  reliable  a  source  of  nitrogen,  as  the  beef.  This  dis- 
covery does  away  with  any  ground  for  the  old  prejudice 
against  veal  as  an  article  of  food. 

187.  Sweetbreads. — Sweetbreads  are  obtained  from 
the  calf.  That  known  as  the  heart-bread  is  the  thymus 
gland.  It  is  round  and  much  more  delicate  than  the  throat- 
bread,  which  is  the  thyroid  gland,  and  is  long  and  thin. 
The  pancreas  or  stomach  bread  is  now  used  very  little. 


1. 

Nock. 

6.  Ribs. 

2. 

Chuck. 

7.   Loin. 

3. 

Shoulder. 

8.  Flank. 

4. 

Fore  shank. 

9.   Leg. 

5. 

Breast. 

10.   Hind  shank 

Fig.  29. — Diagrams  of  cuts  of  veal. 

188.  Lamb  and  Mutton. — The  best  mutton  comes  from 
a  sheep  about  three  years  old.  The  flesh  should  be  fine 
grained  and  dull  red,  while  the  fat  should  be  white,  hard, 
dry,  rather  than  oily,  and  well  distributed  through  the  lean. 

All  lamb  should  be  less  than  a  year  old.  Spring  lamb 
is  from  two  to  three  months  old.  While  the  color  of  the 
flesh  differs  from  that  of  mutton,  the  better  way  of  judging 
between  the  two  is  by  the  bone.  In  lamb  the  ends  of  the 
limb  bones  are  separated  from  the  shaft,  while  in  the  older 
animal  the  ends  become  a  part  of  the  shaft  and  form  one 
bone. 


no 


FOOD 


189.  Cuts  of  Lamb  and  Mutton. — (a)  Hind-quarter: 
Leg;  loin;  flank. 

(6)  Fore-quarter:  Fore  ribs;  breast;  neck. 

Loins. — The  loins  are  used  for  roasts  and  chops.  When 
the  bone  of  the  rib  chop  is  scraped  free  from  meat,  it  is  a 
French  chop.  The  rib  chops  are  considered  more  delicate 
than  the  loin   chops  and  are  more  expensive.     The  loin 


1.  Neck. 

2.  Chuck  or  fore-rib 

3.  Breast. 

4.  Flank. 

5.  Loin. 

6.  Leg. 


Fig.  30. — Diagrams  of  cuts  of  lamb. 


chops,  however,  have  less  bone  and  are  tender  and  fine  in 
flavor.  Shoulder  chops,  when  not  too  high  in  price  and 
from  a  good  animal,  are  very  satisfactory.  ^ 

Breast  and  Flank. — In  mutton  the  breast  and  flank  are 
used  for  stewing,  while  the  breast  of  lamb  is  used  for  both 
stewing  and  braising. 

Neck. — The  neck  of  both  lamb  and  mutton  are  used 
for  stews  and  broth,  and,  if  lean  and  juicy,  may  be  used  for 
casseroles. 


MEATS 


111 


Saddle  of  Lamb  or  Mutton. — The  saddle  is  formed  by 
leaving  the  two  loins  joined  together,  the  carcass  not  being 
split.     This  makes  the  finest  of  the  mutton  roasts. 

Crown  of  Lamb. — This  is  formed  by  Frenching  several 
of  the  rib  chops,  then  fastening  them  together  to  form  a 
circle.  This  is  roasted  and  the  center  filled  with  vegetables 
before  serving. 

190.  Pork. — Pork  is  the  flesh  of  the  hog,  and  because  of 


a.  Head. 

2.  Shoulder. 

3.  Back. 

4    Middle  cut, 

5.  Belly. 

6.  Ham, 

7.  Ribs. 
Loin. 


Fig.  31. — Diagrams  of  cuts  of  pork. 


its  indigestibility  (owing  to  the  large  amount  of  fat  present), 
and  the  possible  presence  of  trichina  or  bladder  worm, 
it  is  less  desirable  for  food  than  the  other  meats.  Good 
pork  is  pale  red  and  the  lean  part  is  firm,  while  the  fat  is 
soft  and  oily.  Pork  should  be  thoroughly  cooked,  as  this 
is  the  only  way  of  killing  any  parasites  that  may  be  present. 
191.  Internal  Organs  Used  as  Food. — The  internal 
organs  of  animals  used  for  food  are:  Brains;  tongue;  heart; 
kidneys;  liver;  sweetbreads;  tripe. 


112  FOOD 

Brains  are  composed  largely  of  fatty  material,  and, 
while  very  readily  digested,  are  absorbed  to  such  a  small 
extent  (43  per  cent)  as  to  make  them  of  slight  food  value. 

Tongue. — While  beef  tongue  is  the  one  that  is  usually 
indicated  when  the  word  tongue  is  used,  calf's  tongue  as  well 
as  lamb's  is  also  used.  The  latter  is  usually  sold  pickled. 
Good  tongue  may  be  recognized  by  its  thickness  and  firm- 
ness. There  should  be  a  plentiful  supply  of  fat  on  the  under 
side. 

Heart  is  very  much  like  ordinary  meat  in  com.position, 
but  being  denser  in  structure  it  is  difficult  of  digestion  unless 
made  tender  by  very  long  cooking. 

Liver  and  Kidneys  are  very  compact  in  structure  and 
contain  no  connective  tissue.  They  are  considered  difficult 
of  digestion,  and  while  they  contain  much  protein,  it  is 
in  a  different  form  from  that  found  in  ordirary  meat. 

Sweetbreads,  also  mentioned  under  veal,  page  109,  are 
cellular  in  structure,  the  cells  being  held  together  by  a  loose, 
delicate  connective  tissue.  On  this  account,  they  are  among 
the  most  easily  digested  of  all  animal  foods. 

Tripe  is  the  cleaned  and  boiled  lining  of  the  stomach 
of  the  beef  animal.  It  is  largely  composed  of  connective 
tissue.  This  may  be  changed  by  boiling  into  gelatin  and  so 
made  very  digestible.  Tripe  has  considerable  fat,  but  owing 
to  the  absence  of  extractives,  has  but  little  flavor. 

192.  Gelatin. — Gelatin  is  obtained  from  bones,  tendons, 
connective  tissue,  skin,  and  from  calves'  feet.  When  pure, 
gelatin  has  no  odor  or  taste  and  is  transparent  and  spark- 
Hng. 

Composition.  Gelatin  is  something  like  protein  in  com- 
position and  is  very  digestible.  Unlike  protein  it  is  not 
capable  of  building  tissue,  but  is  sometimes  used  as  a  pro- 
tein sparer  because  the  body  can  make  use  of  it  in  the  pro- 
duction of  heat  and  energy,  thus  sparing  the  more  valuable 
forms  of  protein.  It  is  much  more  easily  broken  down 
than  the  other  proteins. 


MEATS  113 

EXPERIMENTS 

Experiment  1.  Effect  of  Cold  Water  upon  Meat.— (a)  Cut  raw 
beef  into  very  small  pieces  and  allow  it  to  stand  in  cold  water.  Ob- 
serve the  change  in  the  color  of  the  water  and  of  the  meat.     Explain. 

(6)  Strain  off  the  water  from  (a)  and  heat  it  slowly  in  a  glass  beaker. 
Observe  and  account  for  any  change  in  color  and  the  presence  of  solid 
particles  in  the  water. 

Experiment  2.  Effect  of  Boiling  Water  upon  Meat. — (a)  Place 
small  piece  of  beef  in  a  saucepan  of  rapidly  boiling  water.  Does  the 
water  change  color  as  in  the  above  experiment?     Why? 

Account  for  the  hard  surface  of  the  meat,  and  the  change  in  color 
of  the  outside. 

Experiment  3.  Effect  of  Nitric  Acid  on  Beef  Juice. — Squeeze 
some  of  the  juice  from  raw  beef  and  add  to  it  a  small  amount  of  nitric 
acid.     Account  for  the  result. 

Experiment  4.  Effect  of  Dry  Heat  upon  Tough  Meat. — Scrape  a 
piece  of  raw  beef  until  only  the  connective  tissue  remains.  Place 
the  tissue  on  a  hissing  hot  pan  and  observe.     Explain. 

Experiment  5.  Effect  of  Slow  Cooking  in  Water  below  the  Boiling 
Point  on  Tough  Meat. — Cook  a  small  piece  of  beef  at  180°  F.  until  the 
fibres  can  be  torn  apart.     Explain  the  easy  separation  of  the  fibres. 

SUGGESTIONS  FOR  LABORATORY  PRACTICE 

Cook  tender  meat;   boil  and  pan  broil  steak  and  lamb  chops. 
Cook  tough  meat;  make  soup  stock,  and  brown  stew. 
Use  left-over  meat  in  meat-pie,  hash,  and  sandwiches. 


CHAPTER  XIV 
POULTRY  AND   GAME 

193.  Poultry. — The  domestic  birds  used  for  food  are 
chickens,  fowls,  turkeys,  geese,  ducks,  guinea  fowls,  and 
pigeons. 

194.  Game. — The  more  common  wild  birds  and  animals 
hunted  for  food  are  wild  geese,  wild  ducks,  quail,  partridge, 
reed  birds,  squirrels,  rabbits,  and  deer. 

195.  Composition. — In  poultry  and  game,  as  in  all  other 
flesh  foods,  protein  and  fat  are  the  important  nutrients. 
The  white  meat  or  breast  of  chicken  and  turkey,  has  practi- 
cally the  same  protein  content  but  is  poorer  in  fat  than  the 
dark  meat.  Also  the  flesh  of  a  young  bird  yields  more 
protein  and  less  fat  than  the  flesh  of  a  fowl. 

Poultry  contains,  pound  for  pound,  a  little  more  of  the 
building  material  needed  by  the  body  and  less  of  the  energy- 
giving  materials  than  the  red  meats,  beef  and  mutton. 
However,  poultry  compares  favorably  with  meat  in  the 
amount  of  available  nutrients  furnished  and  is  interchange- 
able with  fish  and  meat  in  the  diet.  Chicken  is  the  cheapest 
kind  of  poultry  and  in  the  matter  of  economy  is  comparable 
with  the  cheaper  cuts  of  beef  and  mutton.  It  also  offers 
an  agreeable  variety  to  the  diet  and  should  be  used  in  place 
of  meat  or  fish  as  the  main  course  of  the  dinner. 

At  the  present  time  game  animals  and  birds  are  con- 
sidered a  luxury,  and  as  such  are  not  an  important  part  of 
the  food  supply  of  the  country.  Game  is  considered  best 
after  it  has  hung  for  some  time  or  until  it  may  be  called 
^'high." 

196.  Digestibility. — From   the    viewpoint    of    complete- 

114 


POULTRY  AND  GAME  115 

ness  of  digestion,  poultry  and  game  may  be  rated  with  the 
other  flesh  foods.  If  considering  the  relative  ease  of  diges- 
tion, chicken  is  more  digestible  than  lean  meat,  while  duck 
and  goose,  because  of  the  larger  percentage  of  fat,  are  on  a 
par  with  pork.  The  light  meat,  or  breast  of  chicken,  is 
composed  of  shorter  and  more  tender  fibres,  contains  less 
connective  tissue  and  usually  less  fat  than  the  dark  meat, 
such  as  leg  muscles.  For  these  reasons  light  meat  is  pre- 
ferable for  children  and  persons  having  weak  digestions. 

197.  Selection. — The  breed  of  fowl,  as  well  as  the  sur- 
roundings and  food,  have  an  influence  upon  the  economy, 
wholesomeness  and  quality  of  the  flesh.  Birds  having 
plump  breasts  and  rounded  legs  are  more  economical  as  well 
as  better  flavored  than  the  large  boned  fowls  bred  for  laying 
qualities  alone.  The  flesh  of  poultry  allowed  to  roam  the 
fields  and  feed  upon  all  kinds  of  food  is  inferior  in  flavor 
and  quality  to  the  flesh  of  chickens  fed  upon  grain  or  pre- 
pared food. 

198.  Picking. — The  best  grade  of  poultry  is  dry  picked. 
Scalding  is  an  easier  way  of  removing  the  feathers,  but  by 
this  method  some  of  the  flavor  is  lost,  while  from  8  to  10 
per  cent  of  water  is  added  for  which  the  consumer  must  pay 
food  prices.  If  the  bird  has  been  dry  picked,  the  flesh 
is  plump,  the  skin  is  flexible,  and  the  fat  on  the  breast  is 
yellow.  A  scalded  chicken  has  a  smooth,  tight-stretched 
skin,  often  rubbed  in  places,  and  the  legs  are  hard  to  bend 
back. 

The  animal  heat  should  be  removed  as  soon  as  the 
fowl  is  picked.  This  should  be  done  by  hanging  in  cool 
dry  air  for  about  twenty-four  hours.  Poultry  should  be 
shipped  in  refrigerator  cars  and  kept  cool  and  dry. 

199.  Chickens. — Young  and  tender  chicken  may  be 
recognized  by  smooth  legs,  a  soft  thin  skin,  and  a  flexible 
breast  bone.  Rough  legs,  heavy  blunt  claws,  thick  rough 
skin,  and  a  hard  breast  bone  all  indicate  age  in  a  fowl. 

The  season  for  broilers  (chicken  from  two  to  four  months 


116  FOOD 

old)  is  from  May  to  October.  Roasting  chickens  are  in 
the  market  from  September  to  December,  inclusive.  Those 
bought  at  other  seasons  are  probably  cold  storage  birds. 

200.  Selecting  Turkeys. — Turkeys  under  one  year  old 
have  black  feet,  a  thin  skin,  and  a  flexible  breast  bone. 
The  season  for  fresh  turkeys  begins  in  November  and  ends 
in  late  February.  Turkeys  weighing  from  fourteen  to 
twenty  pounds  are  preferred  to  the  larger  and  heavier 
birds.  The  choicest  and  finest  turkeys  in  the  market  are 
dry  picked,  and  are  delivered  without  packing  in  ice. 

201.  Ducks  and  Geese. — Spring  ducks  and  geese  begin 
to  reach  the  markets  in  May  and  may  be  had  until  January. 
Old  ducks  and  geese  may  be  obtained  any  season  of  the  year. 
White  Pekin  ducks  are  valued  highly  for  table  use.  They 
weigh  from  six  to  eight  pounds  when  at  their  best.  Geese 
at  sixteen  to  eighteen  pounds  weight  are  considered  prime. 

202.  Squab. — Young  pigeons,  called  squab,  are  prime 
for  eating  when  about  four  weeks  old.  Eight  pounds  to 
the  dozen  is  the  standard  weight  for  squab.  They  are  most 
plentiful  in  the  summer  months,  but  may  be  obtained  all 
the  year  around. 

Pigeons,  which  are  rarely  seen  in  the  markets,  are  much 
cheaper  than  squab.  The  flesh  of  the  pigeon  requires 
special  cooking  to  make  it  tender  and  palatable. 

203.  Guinea  Fowls. — Young  guinea  fowls  are  ready  for 
market  in  the  early  fall.  Old  fowls  are  in  the  market  all 
winter.  The  flesh  of  the  guinea  fowl  is  darker  in  color 
than  that  of  the  common  fowl,  and  the  fibres  are  shorter. 
The  demand  for  guinea  fowl  for  table  use  is  increasing.  In 
flavor  the  fl€sh  resembles  that  of  game  birds. 

204.  Preparation  of  Poultry. — The  average  housekeeper 
prefers  to  have  her  poultry  drawn  (i.e.  internal  organs 
removed)  at  the  market.  Directions  for  the  proper  pro- 
cedure may  be  found  in  any  reliable  cook  book  in  case  they 
are  to  be  prepared  at  home. 

Boiling,  stewing,  roasting  and  broiling  are  the  methods 


POULTRY  AND  GAME  117 

of  cooking  commonly  used  with  poultry.  In  any  method 
the  heat  of  cooking  develops  the  flavors,  kills  micro-organisms 
and  produces  changes  which  render  the  meat  more  appetiz- 
ing by  improving  the  flavor  and  appearance.  Long,  slow 
cooking,  which  softens  the  muscle  fibres  and  connective 
tissue,  should  be  used  with  old  and  tough  birds.  Roasting 
and  broiling  are  the  methods  of  cooking  employed  for  young 
and  tender  birds.  In  these  processes  the  flesh  is  subjected 
to  a  high  temperature  at  first  in  order  to  harden  the  protein 
near  the  surface.  This  forms  a  crust  which  prevents  the 
further  escape  of  the  juices.  After  this  crust  has  been 
formed,  the  temperature  should  be  reduced  to  allow  the  heat 
to  penetrate  to  the  center  without  burning  the  outside. 
Frequent  basting,  or  pouring  the  escaped  juices  over  the 
roasting  meat,  helps  to  form   a  coating  over  the  surface. 

In  roasting  poultry  the  cavity  is  usually  filled  with  stuf- 
fing or  dressing.  This  stuffing  is  a  highly  seasoned  mixture 
which  serves  the  purpose  of  seasoning  the  bird  and  keeping 
it  in  shape.  Some  chefs  prefer  to  roast  birds  without 
stuffing,  contending  that  the  juices  of  the  meat  are  drawn 
out  by  this  dressing,  leaving  the  white  meat  of  the  breast 
dry  and  lacking  in  flavor. 

A  general  rule  for  the  roasting  of  chickens  and  turkeys 
is  to  allow  twenty  minutes  to  the  pound  for  cooking.  Ducks 
and  geese,  because  of  the  amount  of  fat,  require  a  longer 
time  for  the  cooking  process. 

SUGGESTIONS  FOR  LABORATORY  PRACTICE 

In  connection  with  the  study  of  the  text  of  the  preceding  chapter: 
Stuff  and  roast  fowl. 
Broil  chicken. 
Fricassee  of  chicken. 
FrieS  chicken. 


CHAPTER  XV 
FISH 

205.  Quality  and  Flavor. — Fish,  like  meat,  is  a  protein 
food,  but  unlike  meat  it  is  from  one-third  to  two-thirds 
refuse  and  its  flesh  has  a  very  large  amount  cf  water.  Fish 
may  come  from  fresh  or  salt  water;  those  of  much  size 
usually  come  from  lakes  and  the  ocean,  those  of  medium 
size  from  rivers,  and  very  small  ones  are  obtained  from 
brooks. 

The  quality  and  flavor  of  fish  depend  upon  various 
factors,  chief  of  which  are:  The  season,  the  kind  of  water 
in  which  they  live,  the  substances  upon  which  they  feed, 
the  method  of  capture  and  the  way  in  which  they  are 
killed. 

Most  fish  are  best  just  before  spawning,  when  they 
are  said  to  be  in  season.  During  spawning,  fish  are  likely 
to  become  flabby,  with  a  few  exceptions,  such  as  shad  and 
herring,  which  are  at  their  best  at  such  times. 

Fish  that  live  in  deep,  clear,  cool  water  with  a  rocky  or 
sandy  bottom  are  superior  to  those  that  live  in  warm, 
shallow  water  having  a  muddy  bottom.  Fish  which  feed 
upon  Crustacea  and  plant  substance  are  preferable  to  those 
which  feed  upon  sewage  products. 

Fish  should  be  killed  immediately  upon  being  removed 
from  the  water,  for  if  allowed  to  die  slowly,  rapid  decom- 
position results. 

206.  Composition. — While  fish  resembles  meat  in  com- 
position and  contains  the  same  foodstuffs,  there  is  a  dif- 
ference in  the  amounts  present.  The  flesh  of  meat  has 
a  much  higher  percentage  of  fat  than  that  of  fish.     The 

118 


FISH  119 

form  of  protein  known  as  collagen  (a  substance  which  yields 
gelatin  on  boiling)  exists  in  greater  abundance  in  fish 
than  in  meat.  Fish,  unlike  meat,  is  deficient  in  extractives 
and  haemoglobin,  which  explains  the  absence  of  flavor  and 
color  in  this  food.  Mineral  matter  is  present  to  the  extent 
of  about  5  per  cent,  and  occurs  in  the  form  of  phosphates 
of  potash  and  lime  with  some  sodium  chloride.  As  most 
fish  lack  carbohydrates,  they  should  be  eaten  in  combination 
with  some  starchy  food. 

207.  Digestibility. — ^Fish  is  supposed  to  be  more  easily 
digested  than  meat,  doubtless  due  to  the  fact  that  the 
fibres  are  short  and  easily  separated.  Those  kinds  con- 
taining the  smallest  amount  of  fat  are  the  most  digestible. 
The  accumulation  of  uric  acid  in  the  system  is  apt  to  be 
much  less  on  a  fish  than  on  a  meat  diet. 

208.  Choosing  Fish. — While  the  ideal  way  is  to  keep 
fish  alive  in  pools  of  cool  water  until  just  before  cooking, 
this  unfortunately  is  usually  impossible.  Most  market 
fish  are  packed  in  ice  after  having  been  killed,  and  so  kept 
until  sold.  Cold  storage  fish  are  frozen  solid  and  kept  in 
this  condition  until  sold.  Just  how  much  this  treatment 
affects  the  taste  and  wholesomeness  of  the  fish  has  not  yet 
been  determined,  but  fish  so  treated,  if  not  cooked  immedi- 
ately after  thawing,  are  very  likely  to  develop  ptomaines. 
In  choosing  fish  see  that  the  eyes  are  full  and  bright,  the 
gills  red,  the  flesh  firm  and  stiff  with  no  disagreeable 
odor. 

209.  Cooking. — ^Any  method  of  cooking  which  is  appli- 
cable to  meat  may  also  be  applied  to  fish.  The  sooner 
fish  is  cooked  after  it  is  caught  the  finer  the  flavor.  Boiling 
is  considered  the  least  economical  method  of  cooking  fish, 
as  experiment  has  shown  that  when  so  cooked  the  loss  in 
weight  is  between  5  and  30  per  cent.  If  vinegar  or  other 
acid  is  added  to  the  water  in  which  fish  is  boiled,  the  protein 
hardens  more  quickly  and  the  fish  is  prevented  from  falhng 
apart.     Fish  is  cooked  sufficiently  when  the  flesh  becomes 


120  FOOD 

dry  and  opaque  and  separates  easily  from  the  bone.  Serving 
fish  with  lemon  or  some  piquant  sauce  improves  its  flavor 
and  makes  it  acceptable  to  many  who  otherwise  find  it 
tasteless  and  insipid. 

210.  Preserving.— Large  quantities  of  fish  are  preserved 
by  canning,  drying,  smoking,  and  salting.  The  methods 
of  canning  have  now  reached  such  a  degree  of  perfection 
that  much  of  the  original  flavor  of  the  fish  is  retained. 
Canned  fish  is  economical,  as  the  greater  part  of  the  refuse 
has  been  removed  before  canning. 

Dried  fish  usually  loses  about  30  per  cent  of  its  water 
during  the  process  of  drying.  Pound  for  pound  therefore, 
it  is  more  nutritious  than  fresh  fish. 

211.  Common  Food  Fish. — Fish  are  sometimes  classified 
according  to  the  amount  of  fat  which  they  contain. 

(1)  Those  containing  more  than  5  per  cent  of  fat  are: 
salmon,  shad,  herring,  Spanish  mackerel,  and  butter  fish. 

(2)  Those  containing  between  2  and  5  per  cent  of  fat  are : 
white  fish,  mackerel,  mullet,  halibut,  and  porgy. 

(3)  Those  containing  less  than  2  per  cent  of  fat  are: 
smelts,  black  bass,  blue  fish,  hake,  flounder,  yellow  perch, 
pike,  pickerel,  sea  bass,  cod  and  haddock. 

212.  Specially  Prepared  Fish. — Sardines,  so  named 
because  they  were  first  found  off  the  coast  of  Sardinia, 
belong  to  the  herring  family  and  sometimes  small  herrings 
are  substituted  for  them.  Sardines  are  used  fresh  in  Europe 
but  only  canned  in  oil  in  the  United  States. 

Sturgeon  known  as  white  or  Oregon  sturgeon  are  found 
on  the  Pacific  coast.  Some  are  very  large  and  until  quite 
recently  were  appreciated  only  for  their  eggs  or  roe,  from 
which  caviar  is  made.  Caviar  is  prepared  by  removing  the 
eggs  from  the  fish,  then  rubbing  them  to  separate  them 
and  remove  the  membrane  which  envelops  them.  A  certain 
amount  of  salt  is  then  added,  the  first  effect  of  which  is  to 
dry  the  eggs,  but  after  a  time  the  salt  draws  the  water 
from  the  eggs  and  forms  a  brine.     This  brine  is  poured  off 


FISH 


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122  FOOD 

and  the  eggs  are  allowed  to  drain  from  eight  to  twenty  hours 
after  which  they  are  put  in  cans.  The  caviar  is  prized  for 
its  flavor  and  for  its  food  value,  which  is  about  the  same  as 
that  of  the  fish  itself.  In  the  roe  is  found  lecithin  which  is 
a  phosphorized  fat. 

213.  Unusual  Types  of  Fish  Tested  and  Recommended 
by  the  Bureau  of  Fisheries. — Burhet. — This  fish,  though 
little  known,  belongs  to  the  same  family  as  the  cod  and  is 
the  only  one  of  that  family  which  is  found  in  fresh  water. 
The  flesh  is  firm,  white  and  fine  in  flavor,  and  as  it  comes 
to  the  market  skinned,  dressed,  and  without  the  head,  it 
may  be  considered  a  very  cheap  food. 

Bowfin. — This  is  very  good  smoked  and  salted. 

Catfish. — While  not  generally  appreciated  catfish  has 
been  found  to  have  a  very  high  calorific  value  as  food. 
One  pound  of  it  yields  eleven  hundred  calories. 

Sablefish. — Sablefish  is  sometimes  called  black  cod.  This 
fish  is  fine  in  texture  and  of  delicious  flavor.  Although  it 
comes  from  the  deep  waters  of  the  Pacific,  it  can  be  very 
successfully  shipped,  and  so  can  be  obtained  frozen  as  far 
east  as  New  England. 

Gray  fish. — Gray  fish  is  now  appearing  fresh  in  all  markets 
along  the  coast  but  it  is  very  good  canned  or  smoked,  and 
may  be  so  obtained  anywhere. 

Tile  fish  were  first  discovered  off  the  coast  of  Nantucket, 
in  1879,  but  while  its  food  value  was  being  determined  and 
before  it  could  be  placed  upon  the  market,  it  was  completely 
exterminated,  supposedly  by  a  sudden  chilling  of  the  waters 
brought  about  by  the  receding  of  the  Gulf  Stream.  With 
the  return  of  this  current  some  years  later,  the  fish  again 
appeared,  and  it  is  hoped  that  with  an  increasing  knowledge 
of  its  great  food  value,  its  abundance  at  all  seasons,  and  the 
ease  with  which  it  is  captured,  it  may  now  become  of  great 
importance  in  the  fresh  fish  market. 

214.  Shell  Fish. — Under  the  general  name  of  shell  fish 
are  included: 


FISH  123 

(a)  The  mollusks. — Oysters,  clams,  scallops,  and  mussels. 

(6)   The  crustaceans. — Lobsters,  crabs,  and  shrimps. 

Shell  fish,  like  other  fish,  are  used  as  a  source  of  protein 
in  the  diet.  Unlike  the  others  they  contain  the  carbo- 
hydrate substance  glycogen  which  somewhat  increases  their 
food  value.  They  are  expensive,  and  with  few  exceptions 
are  difficult  of  digestion. 

215.  Oysters. — Oysters,  which  are  perhaps  the  most 
used  of  the  shell  fish,  are  found  in  salt  water.  They  vary 
in  size  according  to  the  variety,  and  are  not  eaten  until 
they  are  at  least  two  years  old.  Oysters  were  formerly 
named  from  the  locality  from  which  they  came  but  that 
custom  no  longer  prevails.  For  example,  Blue  Points  were 
originally  a  small  variety  which  came  from  Long  Island, 
New  York.  Now  any  small  variety  not  measuring  more 
than  two  or  two  and  a  half  inches  is  commonly  so-called. 
Saddle  rock  is  a  name  given  to  very  large  oysters. 

Season  oysters  are  at  their  best  from  September  to  May 
on  the  Atlantic  coast.  They  should  be  eaten  as  soon  as 
they  are  removed  from  the  shell.  The  practice  of  opening 
large  quantities  at  a  time  and  keeping  them  in  tubs  until 
purchased  is  to  be  deplored. 

Floated  oysters  are  those  that  have  been  treated  with 
fresh  water  in  order  to  increase  their  size.  They  usually 
lose  flavor  by  this  treatment,  owing  to  the  loss  of  some  of 
their  natural  salts.  There  is  danger  also  of  their  being 
contaminated. 

While  oysters  are  more  easily  digested  when  eaten  without 
cooking  the  ease  with  which  they  transmit  disease  germs 
makes  this  a  dangerous  practice.  Slight  cooking  is  advisable. 
Long  cooking  toughens  the  oyster  and  renders  it  indigestible. 

216.  Clams. — There  are  two  varieties  of  clams,  the 
long,  or  soft  clams,  always  used  in  the  famous  New  England 
clambake,  and  the  round,  or  hard  clam,  usually  to  be  found 
in  the  markets  south  of  New  York. 

Little  Neck  clams  are  a  very  small  round  variety  noted 


124  FOOD 

for  their  fine  flavor.  They  are  usually  eaten  raw  and  take 
the  place  of  oysters  when  the  latter  are  not  in  season.  The 
composition  of  clams  is  about  the  same  as  that  of  other  fish 
but  many  people  find  difficulty  in  digesting  them. 

217.  Mussels. — Mussels  resemble  oysters,  but  the  shell 
is  smoother  and  they  are  found  in  fresh  water.  They  are 
not  very  palatable  and  are  not  extensively  used. 

218.  Lobsters. — Lobster  is  highly  prized  for  its  sweet 
flavor  which  is  due  to  the  large  amount  of  glycogen  that  it 
contains.  It  is  very  expensive,  as  about  50  per  cent  of  it 
is  refuse,  and  is  considered  indigestible  mainly  on  account 
of  the  coarseness  and  density  of  its  fibres. 

219.  Crabs. — Crabs  are  classified  as  hard  shelled  and 
soft  shelled.  Soft  shelled  crabs  are  those  which  have  recently 
shed  their  shell.  The  flesh  of  the  crab  is  more  delicate 
than  the  flesh  of  the  lobster. 

220.  Shrimps. — Shrimps  are  high  in  food  value,  one- 
fourth  their  weight  being  made  up  of  protein.  The  tail  is 
the  only  portion  eaten.     They  are  usuaUy  used  canned. 

221.  Terrapin. — Terrapin  is  a  turtle-like  reptile  found 
in  the  salt  water  of  bays  and  lagoons.  It  is  valuable  for 
the  delicacy  of  its  flesh  as  well  as  for  its  fine  flavor  and 
digestibility.  It  is  scarce  and  very  expensive.  The  diamond 
back  is  considered  the  choicest  variety. 

SUGGESTIONS  FOR  LABORATORY  PRACTICE 

In  connection  with  the  study  of  the  text  of  the  preceding  chapter: 
Broil  mackerel;    bake  bluefish;    boil  cod;    make  clam  chowder; 
scallop  oysters,  fry  scallops. 

Prepare  hollandaise,  tartar,  and  egg  sauce. 


CHAPTER  XVI 
MINERAL  MATTER 

222.  Definition. — The  term  mineral  matter  or  ash  is 
applied  to  those  substances  found  in  food  that  are  produced 
by  the  combination  of  the  elements  calcium,  phosphorus, 
iron,  sodium,  potassium,  magnesium,  chlorine,  silica,  iodine, 
and  flourine  with  food  materials. 

223.  Function  in  Body. — These  substances  are  essential 
as  body  builders  and  as  body  regulators.  In  the  first  instance 
they — especially  the  compounds  of  calcium — furnish  the 
very  important  elements  which  enter  into  the  formation 
of  the  bones,  teeth,  hair,  and  nails.  In  the  absence  of  these 
elements  the  bones  lose  their  rigidity  and  the  muscles  lack 
the  ability  to  contract. 

As  body  regulators  mineral  substances  are  particularly 
valuable  to  certain  fluids  of  the  body,  notably  the  blood, 
which  owes  to  the  iron  in  the  haemoglobin  its  power  of 
holding  oxygen  and  conveying  it  to  other  tissues  in  the 
body.  To  the  presence  of  calcium  the  blood  owes  its  power 
of  coagulation.  The  blood,  as  well  as  other  tissue  depends 
primarily  upon  these  mineral  substances,  for  alkalinity. 
In  experiments  to  determine  the  effect  upon  the  body  of  an 
ash-free  diet  (that  is  a  diet  of  fats,  carbohydrates  and  protein 
from  which  all  mineral  matter  has  been  extracted),  it  was 
found  that,  in  the  absence  of  the  bases  or  alkaline  salts  of 
the  usual  ash  containing  diet,  the  mineral  acids  resulting 
from  the  oxydation  of  food  as  well  as  from  the  body  meta- 
bolism, were  neutralized  so  slowly  that  the  abnormal  con- 
dition known  as  acidosis  resulted.  The  solvent  power 
and  the  power  of  osmosis  (ability  to  pass  through  an  animal 

125 


126  FOOD 

membrane)  possessed  by  many  fluids  of  the  body,  depends 
upon  the  presence  of  these  mineral  substances. 

224.  Sources  of  Mineral  Matter. — The  mineral  sub- 
stances required  by  the  body  are  usually  found  in  combina- 
tion with  other  foodstuffs  and,  as  a  rule,  pass  into  the  blood 
unchanged  by  digestion.  It  is  difficult  to  fix  the  exact 
amount  of  mineral  matter  required  daily,  but  a  well-known 
authority  states  that  only  three  forms  need  special  con- 
sideration. These  are  calcium,  iren,  and  phosphorus. 
Other  forms  of  mineral  matter  probably  occur  in  sufficient 
quantities  in  any  intelligently  planned  diet. 

Calcium. — The  body  contains  about  2  per  cent  of  cal- 
cium which  should  be  maintained  by  the  food.  The  mini- 
mum amount  required  daily  is  0.7  gram  for  an  adult.  A 
larger  amount  should  be  supplied  in  the  food  of  a  growing 
child  to  furnish  material  for  the  growth  of  bones  and  teeth. 
Calcium  helps  in  the  utilization  of  iron  and  has  been  called 
the  ' 'body's  great  harmonizer." 

Iron. — ^The  body  of  average  weight  contains  approxi- 
mately 3  grams  of  iron.  This  should  be  furnished  in  organic 
form,  as  it  is  only  the  iron  in  food  that  can  be  utilized  in 
building  body  tissue.  Iron  in  inorganic  or  medicinal  form 
has  been  found  to  act  only  as  a  stimulant  in  aiding  the 
body  to  manufacture  haemoglobin  from  food  iron.  It  is, 
therefore,  effective  only  when  combined  with  foods  having 
a  high  iron  content.  Iron  is  more  necessary  in  the  diet  of 
women  and  children  than  in  that  of  men. 

Phosphorus. — The  approximate  amount  of  phosphorus 
required  daily  is  4  grams  furnished  in  different  compounds. 
The  appearance  of  this  element  as  phosphorized  fat  in  the 
brain  has  probably  led  to  the  erroneous  belief  that  foods 
rich  in  phosphorus  are  essentially  brain  foods. 

Sodium  Chloride,  or  common  salt,  is  the  only  form  of 
mineral  matter  usually  added  directly  to  the  food.  Often 
more  is  used  than  is  necessary  or  advisable.  Salt  helps  in 
the  production  of  the  hydrochloric  acid  of  the  stomach, 


MINERAL  MATTER  127 

stimulates  the  appetite,  and  produces  the  thirst  which 
encourages  the  drinking  of  more  water  than  many  would 
otherwise  take. 

TABLE  XI —FOODS  RICH  IN   MINERAL   MATTER 

Weight  in  ounces  of  100  calorie  portion 

Almonds ^  oz. 

Beans  (dried) 1    oz. 

Beef  (lean) 2^  oz. 

Carrots 7j  oz. 

Cheese  (cottage) 3j  oz. 

Chocolate |  oz. 

Egg  yolk 1    oz.  (2  yolks) 

Lentils 1    oz. 

Milk  (whole) 5    oz. 

Oatmeal 1    oz. 

Peanuts f  oz. 

Prunes 1^  oz. 

Raisins 1    oz. 

Salmon If  oz. 

Spinach 14f  oz. 

Turnips 9    oz. 

Whole  wheat 1^  oz. 

Lettuce 18|  oz. 

225.  Vitamines. — The  name  vitamines,  meaning  "essen- 
tial to  life/'  has  been  given  to  a  group  of  substances  about 
which  little  is  definitely  known.  Attention  was  first  directed 
to  these  substances  when  it  was  shown  experimentally  that 
artificial  mixtures  of  the  chemical  compounds,  no  matter 
how  scientifically  selected  and  combined,  failed  to  promote 
growth  in  young  animals,  but  that,  by  adding  to  these 
compounds  minute  quantities  of  such  foods  as  egg  yolk, 
milk,  butter  and  cereals,  growth  was  at  once  stimulated 
and  proceeded  in  a  normal  way.  This  led  to  the  belief 
that  there  must  be  in  natural  food  something  besides  pro- 
tein, fat  carbohydrate,  mineral  matter  and  water. 

The  form  in  which  these  vitamines  exist  is  still  a  matter 
of  doubt.     Some  authorities  hold  that,   as  they  exist  in 


128  FOOD 

combination  with  fats,  they  are  themselves  of  a  lipoid  or 
fatty  nature.  Others  claim  that  the  fat  may  serve  only 
the  purpose  of  holding  them  until  called  for  by  the  body. 

226.  Function  of  Vitamines  in  the  Body. — One  form  of 
these  vitamines,  which  has  been  found  to  be  soluble  in  fat, 
has  a  direct  effect  upon  body  growth.  This  form  is  present 
in  the  fat  of  milk,  eggs,  butter,  cod  liver  oil,  muscle  fat, 
and  in  smaller  amount  in  such  cereal  germs  as  those  of 
oats,  rice,  corn,  and  wheat. 

A  second  form,  which  is  found  to  be  soluble  in  water 
and  alcohol,  is  supposed  to  have  some  marked  effect  upon 
nerve  tissue  and  nerve  activity.  This  form  is  found  in  eggs, 
meat,  milk,  and  the  outer  layers,  of  bran,  wheat,  rice, 
corn,  and  oats. 

While  these  vitamines  are  required  only  in  small  amounts, 
their  absence  has  a  disastrous  effect  upon  the  process  of 
nutrition.  Therefore,  foods  treated  in  such  a  way  as  to 
diminish  their  vitamine  content  should  not  be  depended 
upon  exclusively  for  nourishment.  Such  processes  as  can- 
ning, drying,  boiling  (in  some  cases,  as  for  example  milk), 
as  well  as  long  keeping  and  too  great  refining  diminish 
the  vitamines. 


CHAPTER  XVII 
BEVERAGES 

Besides  water  there  are  a  number  of  beverages  which 
are  taken  mainly  for  their  pleasant  flavor  and  stimulating 
effect.  Tea,  coffee,  chocolate,  and  cocoa  belong  to  this 
class. 

227.  Tea. — Tea  is  made  from  the  leaves  and  buds  of  a 


Fig.  32.— Tea  plant.     (Bailey.) 

species  of  evergreen  shrub.  Fig.  32,  which  grows  from  3  to  6 
feet  in  height.  The  cultivation  of  the  tea  plant  is  an  im- 
portant industry  in  China,  Japan,  India,  and  Ceylon.  It 
promises  to  become  a  considerable  factor  in  the  industries 
of  the  Southern  States,  where  the  climate  is  fairly  well 
suited  to  the  growth  of  tropical  plants. 

228.  Composition  of  Tea. — The  chemical  constituents 
of  tea  are  found  to  be  principally  an  alkaloid,  formerly 
called  theiney  but  now  known  as  caffein,  and    said  to  be 

129 


130  FOOD 

identical  with  the  same  substance  found  in  coffee,  tannin, 
certain  volatile  oils,  and  mineral  matter  in  the  form  of 
oxalates. 

Caffein  is  mildly  stimulating  to  the  nerves  and  is  easily 
dissolved  in  boiling  water. 

Tannin,  an  astringent  substance  found  also  in  certain 
fruits  and  vegetables,  is  less  easily  dissolved  in  boiling 
water.     Upon  this  fact  depends  the  principle  of  tea  infusion. 

229.  Classes  of  Tea. — There  are  two  general  classes  of 
tea,  black  and  green.  The  two  kinds  may  be  made  from 
the  same  leaves,  the  main  difference  being  in  the  process 
of  curing. 

Black  tea  is  prepared  by  allowing  the  leaves  to  stand 
and  ferment  before  they  are  dried.  This  changes  the  color 
and  flavor  and  renders  the  tannin  less  soluble.  An  infusion 
of  green  tea  therefore  contains  more  tannin  than  a  like 
infusion  of  black  tea. 

Green  tea  is  made  by  drying  the  leaves  quickly  while  yet 
fresh.  A  green  tea  infusion  has  a  pale  color  and  a  less 
pungent  odor. 

230.  Grades  of  Tea. — The  choice  brands  of  tea  are 
made  from  the  very  young  buds  and  leaves.  The  older 
and  larger  leaves  form  the  less  desirable  and  cheaper  quali- 
ties.    The  finest  quality  of  China  tea  is  flowery  pecoe,  made 

from  the  leaf  buds.  The 
next  larger  leaves  form  orange 
\  pecoe,  the  still  older  and 
^  larger  leaves  pecoe,  and  the 
largest  leaves  a  still  lower 
grade  called  souchong. 

231.  Adulterants  of  Tea. 
Fig.  33.-Tea  leaf.  _^^^  ^^  ^^^  ^^^  shipped  into 

this  country  is  tested  before  it  is  distributed  to  make  sure 
that  it  comes  up  to  the  prescribed  standard  of  purity. 
Coloring  matters  are  sometimes  used  to  improve  the  appear- 
ance of  the  tea  leaves.     These  are  also  frequently  used  on 


BEVERAGES 


131 


spent  leaves,  or  tea  that  has  been  infused,  to  give  it  the 
appearance  of  fresh  leaves.  Probably  the  usual  way  of 
adulterating  tea  is  by  the  addition  of  foreign  leaves  or 
leaves  resembling  the  tea  leaf  in  size  and  shape.  The 
expert  can  detect  these  upon  close  examination,  for  the 


Courtesy  oj  Bleeckers  &  Simon. 

Fig.  34.— Coffee  plant. 

veining  and  midrib  of  the  tea  leaf  are  peculiar  to  this  partic- 
ular plant,  see  Fig.  33. 

232.  Coffee. — Coffee  is  the  fruit  of  a  shrub  or  tree 
which  under  cultivation  grows  from  7  to  16  feet  in  height. 
The  fruit.  Fig.  34,  resembles  a  cherry,  the  beans  correspond- 
ing to  the  pit.  T\yo  beans  grow,  flat  sides  together,  in  the 
pulp,  enclosed  in  a  tough  hull.  The  fruit  is  dried  and  the 
husk  removed  from  the  berries. 


132  FOOD 

The  coffee  growing  countries  rank,  according  to  the 
amount  produced,  as  follows : 

(1)  Brazil,  which  furnishes  more  than  half  of  the  world's 
supply. 

(2)  Mexico  and  Central  America. 

(3)  Africa  and  Arabia. 

(4)  Asia. 

Caffein  and  tannin,  mentioned  under  tea,  are  equally 
important  constituents  of  coffee.  In  addition  to  these  and 
of  equal  importance,  may  be  considered  the  volatile  oil 
caffeol,  which  imparts  to  coffee  its  characteristic  flavor  and 
aroma. 

233.  Mocha  and  Java  Coffee. — The  terms  Mocha  and 
Java  no  longer  indicate  the  source  of  the  coffee,  but 
are  simply  trade  names  signifying  the  quality  of  the 
blend. 

234.  Preparation  of  Coffee. — For  use  as  a  beverage,  the 
coffee  beans  must  first  be  roasted  and  then  ground.  The 
degree  of  fineness  to  which  they  should  be  ground  depends 
upon  the  method  of  preparing  the  beverage.  In  finely 
ground  coffee  the  cells  are  opened  and  the  aromatic  oils 
are  dissolved  by  boiling  water.  It  is  generally  maintained 
that  the  longer  coffee  beans  are  kept  before  roasting  the 
better,  but  that  after  the  roasting  and  grinding  processes 
take  place  the  flavor  escapes  in  the  air  and  the  mixture 
deteriorates  rapidly.  Hence,  when  possible,  it  is  desirable 
to  roast  only  small  quantities  at  a  time  and  to  grind  only 
for  immediate  use.  Roasting  develops  the  caffeol  and 
must  be  done  with  care  to  prevent  the  burning  of  the  smaller 
or  more  immature  berries.  When  this  occurs,  a  bitter  taste 
is  imparted  to  the  whole  mixture. 

235.  Substitutes  and  Adulterants  for  Coffee. — Chief 
among  the  coffee  substitutes  are  the  cereal  coffees  of  which 
Postum  is  typical.  Kaffee  Hag  and  de  Koffer  are  both  prep- 
arations of  the  coffee  bean  after  the  greater  part  of  the 
caffein  has  been  extracted.     It  is  believed  that  these  prepara- 


BEVERAGES 


133 


tions  may  be  used  safely  by  persons  unable  to  stand  the 
stimulating  effect  of  true  coffee. 

Chicory  is  the  common  adulterant  of  coffee,  although 
dried  peas,  beans,  and  grains  are  added  to  ground  coffee 
to  increase  the  amount.  The  inferior  beans  are  also  coated 
or  glazed  with  substances  that  will  improve  their  appear- 
ance. 

236.  Chocolate  and  Cocoa. — Chocolate  and  cocoa  are 
made  from  the  cocoa  bean,  which 
is  the  seed  of  a  native  Central 
American  tree.  The  fruit  of  the 
cocoa  tree.  Fig.  35,  grows  about 
10  inches  long  and  4  inches  thick 
and  has  imbedded  in  the  pulp  20 
to  40  seeds  about  the  size  of  ordi- 
nary almonds.  When  the  fruit 
matures,  these  seeds  are  removed 
and  dried  by  the  heat  of  the  sun. 
The  next  step  in  the  manufac- 
ture of  chocolate  is  that  of  roast- 
ing and  the  removing  of  the 
shells.  After  this  is  done  the 
beans    are    coarsely   crushed    to 

form  cocoa  nibs.  The  nibs  are  ground  extremely  fine,  form- 
ing a  thick  paste  which,  when  allowed  to  cool,  hardens 
into  a  firm  mass  or  cake. 

Cocoa  is  the  finely  ground  form  of  chocolate  after  most 
of  the  fat  has  been  removed  by  pressure. 

Chocolate  and  cocoa  contain  a  stimulating  principle 
closely  related  to  caffein  although  milder  in  action,  called 
theobromin.  In  addition  to  quite  a  high  percentage  of  fat, 
the  cocoa  bean  contains  about  15  per  cent  of  starch,  a  small 
amount  of  protein,  and  mineral  matter.  These  give  choco- 
late and  cocoa  a  distinct  food  value.  The  fat,  when 
extracted,  is  known  as  cocoa  butter  and  is  used  in  toilet 
preparations. 


Fig.  35. — Cocoa  beans. 


134  FOOD 

237.  Effects  of  Tea,  Coffee  and  Cocoa  on  the  Body. — 

The  food  value  of  tea  and  coffee  is  due  to  the  cream  and 
sugar  added  rather  than  to  the  nutrients  found  in  these 
compounds. 

The  exciting  and  stimulating  effect  of  tea,  coffee,  and 
cocoa  is  due  to  the  caffein  or  similar  compounds  present. 
A  cup  of  hot  tea,  by  its  agreeable  flavor  and  stimulating 
action  upon  the  body,  dispels  the  feeling  of  fatigue.  This 
stimulating  effect  upon  the  heart,  kidneys,  and  nervous 
system  varies  with  different  people.  In  some  cases  the 
reaction  of  the  stimulant  is  not  noticeable,  in  others  the 
action  of  the  heart  is  increased  very  perceptibly.  This 
increased  action  of  the  heart  has  a  direct  effect  upon  the 
secretions  of  the  cells  of  the  kidneys. 

Tannic  acid  in  excessive  amounts  precipitates  the 
pepsin  of  the  gastric  juice.  This  interferes  with  the  diges- 
tion of  protein  foods.  The  small  amounts  of  tannic  acid 
occurring  in  properly  made  tea  and  coffee  can  do  no  more 
than  to  retard  the  digestive  process.  In  some  cases  this 
might  be  desirable.  For  example  a  cup  of  black  coffee  after  a 
hearty  dinner  delays  the  action  of  the  juices  upon  protein 
foods  and  at  the  same  time  allows  others  to  be  digested 
in  the  normal  manner. 

The  volatile  oils  of  tea  and  coffee  affect  the  body  in 
slightly  different  ways.  Those  in  the  former  tend  to  open 
the  pores  of  the  skin  and  keep  the  body  moist,  while  those 
of  the  latter  tend  to  have  the  opposite  action.  This  explains 
why  tea  is  given  to  warm  the  body  when  cold,  by  increasing 
the  circulation,  and  to  cool  it  when  heated  by  increasing 
the  surface  evaporation. 

Such  beverages  as  chocolate  and  cocoa  have  a  definite 
nutritive  value  in  themselves,  which  is  increased  materially 
by  the  milk,  cream,  and  sugar  used  in  their  preparation. 
The  mild  action  of  the  stimulating  principle  theobromin 
makes  cocoa  a  more  desirable  drink  for  children.  Tea  and 
coffee,  because  of  their  irritating  effect  upon  the  delicate 


BEVERAGES  135 

mucous  membrane  of  the  digestive  tract  and  their  stimulat- 
ing action  upon  the  heart  and  nervous  system,  are  con- 
sidered most  harmful  to  yoimg  persons. 

EXPERIMENTS 

Experiment  1.    Test  for  the  Presence  of  Chicory  in  Coffee. — Add 

one  teaspoonful  of  the  ground  suspected  coffee  to  a  glass  of  cold  water. 
If  chicory  is  present,  it  will  make  a  brown  streak  as  it  sinks  to  the 
bottom  of  the  glass. 

Experiment  2.  To  Detect  Coffee  Substitutes. — (a)  Add  a  table- 
spoonful  of  the  ground  coffee  to  a  glass  of  water  and  note  the  length  of 
time  it  remains  on  top  of  the  water.  Coffee  will  float  for  some  time, 
as  it  contains  a  little  oil.  Coffee  substitutes  are  heavier  than  the 
coffee  and  quickly  sink  to  the  bottom  of  the  glass. 

(6)  Many  of  the  substitutes  contain  starch,  which  gives  the  char- 
acteristic blue  test  with  iodine.  Boil  one  tablespoonful  of  coffee  in  one 
cup  of  water  for  three  minutes.  Filter  and  cool,  and  then  add  a  few 
drops  of  iodine.  The  appearance  of  a  blue  color  indicates  the  presence 
of  starch. 

SUGGESTIONS  FOR  LABORATORY  PRACTICE 

In  connection  with  the  study  of  the  text  of  the  preceding  chapter, 
prepare: 

Tea  and  coffee. 
Fruit  punches. 


CHAPTER  XVIII 
CONDIMENTS    AND    OTHER    FOOD    ACCESSORIES 

238.  Value. — Condiments  and  other  food  accessories 
do  not,  as  a  rule,  have  a  definite  food  value.  That  is,  they 
do  not  supply  building  material  or  furnish  energy  to  the 
body,  although  they  may  be  considered  body  regulating 
substances  in  that  they  stimulate  the  flow  of  the  digestive 
juices.  For  this  reason  they  may  be  counted  as  essential 
constituents  of  the  normal  diet.  Many  foods,  otherwise 
insipid,  are  made  palatable  by  the  addition  of  simple  con- 
diments to  produce  a  pleasing  flavor. 

239.  Salt. — Salt  is  probably  the  only  condiment  that  is 
absolutely  necessary  for  the  maintenance  of  health.  Salt 
is  obtained  in  various  ways,  chiefly  by  mining  rock  salt 
or  by  pumping  brine  out  of  salt  wells,  salt  lakes,  or  the  ocean, 
and  evaporating  it  in  the  sun.  This  crude  product  is  refined 
for  use.  About  nine-tenths  of  the  large  yearly  output  of 
this  country  comes  from  New  York,  Michigan,  Kansas 
and  Ohio. 

It  has  been  demonstrated  by  experiments  that  high 
grade  or  dairy  salt  is  nearly  pure  (97  to  99  per  cent)  sodium 
chloride.  For  table  use,  salt  is  frequently  mixed  with 
starch  or  some  other  substance  to  keep  it  from  gathering 
moisture  from  the  air.  In  this  event  the  product  should 
be  and  usually  is  labeled  to  show  this  addition. 

240.  Vinegar. — Vinegar  is  one  of  the  most  useful  of  the 
unclassified  foods.  Its  flavor  is  stimulating  and  its  action 
in  softening  the  fibres  of  tough  meat  and  the  tough  cellulose 
of  green  vegetables  is  illustrated  in  the  use  of  vinegar  in 
preparing  mint  sauce  for  lamb,  and  in  French  dressing  to 
be  eaten  with  salad. 

136 


CONDIMENTS  AND  OTHER  FOOD  ACCESSORIES      137 

The  original  term  'Vinegar,"  meaning  only  a  wine 
product,  has  come  to  have  a  broader  meaning  and  to  include 
the  cider,  malt,  and  sugar  products. 

Cider  vinegar  is  made  from  the  juice  of  apples.  This 
ferments  on  standing  and  produces  acetic  acid.  Cider 
vinegar  is  yellow  or  brownish  in  color  and  has  the  odor  of 
apples.     It  also  contains  the  malic  acid  of  the  apple  juice. 

Wine  vinegar  is  a  similar  product  made  from  the  juice 
of  grapes.  For  table  use  white  wine  vinegar,  from  the 
white  grape,  is  considered  superior  to  the  red,  which  is 
made  from  the  juice  of  the  purple  grape.  Tartaric  acid, 
the  characteristic  acid  product  of  the  grape,  is  found  in 
wine  vinegars. 

Sugar  vinegar  is  the  result  of  the  fermentation  of  sugar, 
syrup,  or  molasses  solutions. 

241.  Spices. — Most  spices  owe  their  characteristic  taste 
and  odor  to  the  presence  of  some  one  of  the  volatile  oils. 
Since  their  chief  effect  is  to  stimulate  the  appetite,  their  use 
is  not  advised  in  the  diet  of  children. 

Ground  spice  is  more  often  adulterated  than  whole  spice. 
The  detection  of  finely  ground  foreign  matter,  such  as 
flour  or  other  starchy  or  fibrous  materials,  is  rather  difficult 
in  the  ground  products.  Whole  spices  are  frequently 
adulterated  by  removing  a  part  of  the  important  constituents 
of  the  berries. 

Allspice  is  the  dried  fruit  of  an  evergreen  tree  grown 
in  the  West  Indies.  The  berries  are  gathered  when  full 
grown  but  while  they  are  still  green.  Allspice  receives  its 
name  from  its  resemblance  in  taste  to  a  mixture  of  ground 
cinnamon,  cloves,  and  nutmeg. 

Anise  is  the  seed  of  a  plant  of  the  parsley  family  native 
to  Africa  but  now  cultivated  elsewhere.  It  is  used  in  breads 
and  other  foods. 

Bay  Leaf  is  the  dried  aromatic  leaf  of  a  species  of  laurel. 

Capers  are  the  dried  flower  buds  of  the  caper  plant.  This 
bush,  a  native  of  Southern  Europe,  grows  from  3  to  5  feet 


138  FOOD 

in  height.  The  flower  buds  are  gathered  when  about  the 
size  of  a  pea  and  are  preserved  by  pickHng  in  vinegar. 

Celery  seeds  obtained  from  the  common  plant  are  used 
as  a  seasoning  substance  either  ground  or  in  the  form  of  an 
extract. 

Cinnamon  is  the  inner  bark  of  a  small  tree  grown  in 
Ceylon.  It  has  an  agreeable  odor  and  flavor  and  is  used  as 
a  medicine  as  well  as  a  flavoring  matter. 

Cloves  are  the  dried  flower  buds  of  the  clove  tree,  an 
evergreen  grown  in  the  West  Indies  and  other  places. 

Ginger  is  the  starchy  root  of  a  plant  of  Southern  Asia. 
Ginger  is,  therefore,  a  food  as  well  as  a  condiment.  The 
rhizome,  or  underground  stem,  is  dried  and  sold  as  root 
ginger,  or  ground  finely,  for  powdered  ginger.  The  young 
roots  are  sometimes  cooked  and  preserved  in  syrup  for  the 
preserved  ginger  of  the  market,  or  crystallized  by  boiling 
in  sugar. 

Nutmeg  is  the  dried  seed  of  the  fruit  of  the  nutmeg  tree. 
The  unground  nut  is  commonly  used,  the  spice  grated  into 
the  food  as  desired.  It  is  preferred  in  this  way  since  it 
loses  flavor  readily  when  ground. 

Mace  is  obtained  from  the  surrounding  membrane  of  the 
nutmeg. 

Pepper  is  the  berry  of  a  climbing  plant  found  in  tropical 
climates.  Black  pepper  is  the  ground  berry  before  it  ripens. 
White  pepper  the  ground  berry  after  it  ripens. 

Cayenne  pepper  is  made  from  the  pod  of  a  species  of 
Capsicum.  It  is  a  strong  irritant  to  the  skin  and  mucous 
membrane. 

Paprika  is  the  ground  ripe  fruit  of  the  capsicum,  the 
seeds  and  stems  having  been  carefully  removed  before 
grinding. 

Mustard  is  obtained  from  the  seeds  of  the  black  or  white 
mustard  plant.  Mustard  grows  wild  in  some  localities 
and  is  also  extensively  cultivated.  The  white  mustard 
seeds  are  sometimes  used  whole  in  pickles  and  relishes. 


CONDIMENTS  AND  OTHER  FOOD  ACCESSORIES     139 

Prepared  mustard  is  made  by  grinding  the  seeds  and  mixing 
with  other  spices  and  oils  or  vinegar.  Ground  mustard, 
when  appHed  to  the  skin,  acts  as  a  counter  irritant  and  is 
often  useful  in  relieving  acute  pain. 

SaSe  is  a  common  garden  plant,  the  dried  leaves  of 
which/  are  used  extensively  in  the  preparation  of  sausage, 
and  as  a  seasoning  for  other  meats,  poultry,  and  dressings 
of  various  kinds. 

Tmjvie  is  a  perennial  plant  growing  in  the  form  of  a 
small  shrub  6  to  10  inches  high.  The  leaves  and  young 
shoots  are  used  for  seasoning  purposes. 

242.  Flavoring  Extracts. — Of  the  relatively  large  num- 
ber of  flavoring  extracts  made,  the  extracts  of  vanilla,  lemon, 
and  almond  are  the  ones  universally  used. 

Vanilla  extract  is  made  from  the  vanilla  bean,  which 
is  the  fruit  of  a  climbing  vine  belonging  to  the  orchid  family. 
Those  grown  in  Mexico  are  considered  of  a  superior  quality. 
The  beans  are  allowed  to  ferment  before  drying  to  develop 
the  characteristic  properties.  The  extract  which  is  sold  for 
flavoring  purposes  is  made  by  soaking  the  beans  in  alcohol. 
This  fact  accounts  for  the  loss  of  flavor  by  evaporation, 
especially  in  hot  foods. 

Lemon  extract  is  obtained  by  soaking  lemon  peel  in 
alcohol,  which  extracts  the  volatile  oil  needed  as  a  flavoring 
substance. 

Almond  extract  is  a  flavoring  substance  prepared  by  soak- 
ing the  seed  of  the  bitter  almond  in  alcohol. 


CHAPTER  XIX 
FOOD   REQUIREMENTS   OF  THE  BODY 

243.  Necessity  for  Food. — The  body  requires  food  in 
definite  quantities  for  three  well-defined  purposes:  (1)  To 
furnish  energy;  (2)  to  provide  material  for  growth  and 
repair;  (3)  to  satisfy  its  need  for  those  substances  which 
stimulate  growth  and  regulate  body  processes. 

244.  Amount  Required. — Several  factors  determine  the 
amount  of  food  required  daity  for  a  given  individual,  but 
the  chief  ones  are  age,  weight,  and  activity  of  the  body. 

To  estimate  the  amount  of  food  necessary  to  fulfill  the 
first  requirement,  that  of  supplying  energy,  should  be  no 
more  difficult  than  to  estimate  the  amount  of  gasoline  which 
an  engine  will  use  in  running  a  certain  number  of  miles. 
As  the  fuel  value  of  food  is  reckoned  in  terms  of  a  unit  known 
as  the  calorie,  it  is  most  essential  to  know  exactly  what  is 
meant  by  the  term.  As  the  number  of  calories  required 
will  vary  with  the  body  weight  and  the  degree  of  activity, 
it  will  be  necessary  to  know  how  many  calories  per  pound 
of  body  weight,  per  day,  will  be  used  under  these  varying 
conditions.  And  finally,  as  the  calories  are  yielded  by  the 
oxidizable  foodstuffs  such  as  protein,  fat,  and  carbohydrates, 
it  will  be  necessary  to  know  the  proportion  of  these  present 
in  the  food  materials,  and  to  know  how  many  calories  a 
given  amount  of  each  will  yield. 

By  a  calorie  is  meant  that  amount  of  heat  which  will  raise 
the  temperature  of  one  pound  of  water  four  degrees  Fahrenheit. 

The  number  of  calories  required  by  an  adult  has  been 
found  by  scientific  experiments  to  approximate  the  fol- 
lowing: 

140 


FOOD  REQUIREMENTS  OF  THE  BODY  141 

At  rest 13  to  14  calories  per  lb.,  per  day. 

At  light  exercise 16  to  18  calories  per  lb.,  per  day. 

At  moderate  exercise 18  to  20  calories  per  lb.,  per  day. 

At  severe  exercise 20  to  23  calories  per  lb.,  per  day. 

Using  the  above  data,  it  will  be  seen  that  a  person 
weighing  150  lbs.  and  taking  no  exercise  will  require  150X14 
or  2100  calories  per  day.  The  same  person  exercising 
severely  will  require  as  high  as  150X23  or  3450  calories  per 
day. 

245.  Computation  cf  Energy  Value  of  Foods. — The  \/ 
necessary  information  regarding  the  proportion,  in  terms  of 
grams,  of  the  foodstuffs  in  various  food  materials,  may 
readily  be  obtained  from  any  of  the  Government  Bulletins- 
As  each  of  these  foodstuffs  yields  a  certain  number  of 
calories,  the  protein  and  carbohydrates  yielding  4  calories 
per  gram,  and  the  fat  yielding  9  calories  per  gram,  the  total 
calories,  furnished  by  a  given  amount  of  food  may.  readily 
be  computed. 

Example. — To  determine  the  total  energy  in  calories  furnished  by 
one  pound  of  white  bread.  One  pound  of  white  bread  contains  41.27 
grams  of  protein,  7.26  grams  of  fat,  and  241. 7Si  grams  of  carbohydrates. 
The  energy  furnished  is  therefore: 

By  the  protein,  41.27X4=   165.08  calories 

By  the  fat,  7.26X9=     64.35  calories 

By  the  carbohydrate,  241.75X4=  967.00  calories 

Total  energy  1197.42  calories 

246.  Requirement  for  Growth  and  Repair. — The  second  \ 

requirement  is  often  spoken  of  as  the  protein  requirement 
of  the  body,  as  it  is  upon  protein  that  the  body  chiefly 
depends  for  growth  and  repair  may  also  be  estimated  in 
terms  of  calories.  One  way  of  making  certain  that  this 
protein  requirement  is  met  is  to  see  that  from  one-eighth  to 
one-tenth  the  total  calories  of  the  day's  rations  are  derived 
from  protein  foods.     Another  way  is  to  allow  from  2  to  3 


142  FOOD 

protein  calories  for  each  pound  of  body  weight  for  an  adult, 
and  from  4  to  6  protein  calories  per  pound  of  body  weight 
for  a  growing  child. 

247.  Requirement  for  Body  Regulation. — To  satisfy  the 
body's  third  requirement,  that  is,  its  need  of  growth  stimula- 
ting and  process-regulating  substances,  is,  at  the  present 
time,  by  no  means  a  definite,  well  understood  task.  All 
that  can  be  done  along  this  line,  in  the  light  of  present 
investigations,  is  to  make  an  intelligent  use  of  all  foods. 
In  this  way  a  sufficient  quantity  of  these  substances  to 
meet  the  needs  of  the  body  is  reasonably  well  assured. 

SUGGESTIONS  FOR  LABORATORY  PRACTICE 

In  connection  with  the  text  of  the  previous  chapter  each  pupil 
should  calculate  her  own  food  requirement  per  day. 

Weigh  and  compare  the  100  calorie  portion  of  several  of  the  common 
food  materials. 


CHAPTER  XX 

FOOD   COMBINATIONS   IN  MEALS 

The  food  requirements  of  the  body  have  been  defined 
in  the  previous  chapter.  In  the  present  chapter  the  ques- 
tion of  the  combinations  of  foods  that  will  meet  these 
requirements  will  be  discussed. 

248.  Planning  Meals. — Planning  satisfying  meals  in- 
volves, first  of  all,  a  definite  idea  of  the  family  income  and 
of  what  part  of  this  can  properly  be  appropriated  for  feeding 
the  family. 

The  wise  expenditure  of  money  thus  set  aside  falls  upon 
the  housekeeper.  The  degree  of  success  she  will  achieve 
in  her  efforts  will  depend  upon  her  knowledge  of  the  body 
needs  of  each  individual  under  her  care  and  of  the  kinds 
of  foods  that  will  best  supply  these  needs.  She  must  know 
the  seasons  at  which  various  food  supplies  are  most  plentiful, 
and  therefore  best  and  cheapest,  and  how  to  select,  prepare, 
and  serve  them  in  an  attractive  manner.  By  satisfying 
meals  is  meant  meals  that  satisfy  hunger  and  please  the 
taste,  as  well  as  meet  the  body  requirements. 

249.  Per  Cent  of  Income  to  be  Set  Aside. — Catering 
for  a  group  of  normal  adults  with  all  necessity  for  considering 
the  cost  of  food  eliminated  would  be  a  comparatively  simple 
task.  But  the  present  pressure  upon  the  economic  side, 
due  to  the  high  cost  of  the  staple  foods,  is  forcing  the  house- 
keeper to  exercise  the  greatest  care  and  judgment  in  the 
expenditure  of  the  food  allowance.  Just  what  percentage 
of  the  income  this  allowance  should  be,  depends  upon  many 
things,  but  chiefly  upon  the  amount  of  the  income.  The 
smaller  the  yearly  income,  the  higher  the  percentage  that 

143 


144 


FOOD 


Photo  by  Paul  Thompson 

Fig.  36. 


FOOD  COMBINATIONS  IN  MEALS  145 

must  be  allowed  for  food.  It  has  been  estimated  that, 
in  normal  times,  25  per  cent  of  an  income  of  between  $1500 
and  $2000  will  furnish  adequate  nourishment  for  the  average 
family. 

250.  The  Food  of  Adults  and  of  Children. — From  the 
standpoint  of  nutrition,  the  planning  of  meals  resolves  itself 
into  something  more  complicated  than  the  mere  satisfying 
of  hunger.  The  housekeeper  must  take  into  consideration 
the  age  and  growth  needs  of  the  children  and  the  occupation 
and  amount  of  exercise  taken  by  each  member  of  the  family, 
in  order  to  be  able  adequately  to  judge  the  kind  and  amount 
of  food  required  by  each.  The  man  at  active  muscular 
work  will  use  up  more  calories  than  the  man  of  sedentary 
habits,  and  will  be  able  to  digest  with  ease  the  heartier  foods. 
Children  require  special  attention  with  regard  to  the  supply 
of  growth  stimulating  foods.  It  is  an  established  fact  that 
a  man  can  dispense  with  such  foods  as  eggs,  milk,  cream, 
and  butter  better  than  the  women  and  children  of  the 
family. 

251.  The  Cost  of  Foods.— Important  considerations  in 
planning  meals  are  the  cost  not  only  of  the  raw  food  materials 
but  of  the  fuel  consumed,  and  the  time  and  labor  required 
in  their  preparation. 

The  problem  of  the  cost  of  living  is  becoming  more  and 
more  serious  every  year.  Whatever  the  reason  for  the 
increase  in  the  price  of  food,  it  is  quite  certain  that  former 
low  prices  will  not  be  restored.  Fuel  is  more  expensive. 
Wages  of  domestic  help  are  higher.  Apparently  the  only 
way  by  which  to  combat  these  conditions  is  through  more 
careful  and  intelligent  buying.  By  studying  market  con- 
ditions cheaper  foods,  equally  wholesome  and  identical  in 
nutritive  value,  may  be  substituted  for  high  priced  foods. 

Judicious  buying  implies  a  knowledge  of  the  different 
cuts  of  meat  and  their  possibilities,  and  the  ability  to  dis- 
tinguish between  waste  (bone  and  gristle)  and  solid  meat. 
Judgment  in  buying  staple  goods  in  quantities  whenever 


146  FOOD 

possible,  and  in  buying  perishable  goods  in  season,  as  well 
as  an  understanding  of  their  value  and  place  in  the  diet, 
is  gained  by  study  and  experience.  This  knowledge  and 
experience  may  be  possessed  by  every  housewife  who  is 
willing  to  expend  the  necessary  time  and  effort. 

False  economy  in  food  results  in  a  poorly  nourished 
family,  the  members  of  which  are  readily  susceptible  to 
disease  because  their  resisting  powers  are  not  kept  high 
by  proper  nourishment.  It  should  be  remembered  that 
money  saved  on  food  is  often  spent  on  doctor's  Ijills. 

252.  Balanced  Meals. — To  so  plan  each  meal  as  to  supply 
a  definitely  prescribed  amount  of  each  foodstuff  is  an  impos- 
sible task.  The  one  time  much  over-worked  term,  ''bal- 
anced meals,"  has  therefore  lost  its  implied  meaning  of 
furnishing  the  correct  proportion  of  the  foodstuffs  for  each 
meal.  In  its  newer  and  broader  sense,  the  term  signifies 
providing  a  well-selected  variety  of  foods  which  will  furnish 
a  well-rounded  diet.  In  the  course  of  the  day  such  a  diet 
will  offer  a  sufficient  amount  of  all  kinds  of  foodstuffs  and 
will  thus  meet  all  the  various  requirements  of  the  body. 

253.  Variety  in  Diet. — The  old  saying,  'Variety  is  the 
spice  of  life,"  holds  good  in  the  planning  of  meals.  Effort 
should  be  made  by  the  housekeeper  to  furnish  variety  and 
novelty  in  the  preparation  and  serving  of  the  more  common 
foods  in  order  to  tempt  the  appetite  and  relieve  the  monotony 
of  the  ordinary  diet. 

\  Great  variety  is  not  desirable  at  one  meal,  but  the 
serving  of  any  food  prepared  in  the  same  way  day  after  day 
is  the  surest  way  of  making  it  a  drug  on  the  appetite.  With 
over  two  hundred  ways  of  cooking  eggs,  for  instance,  it 
is  possible  to  surprise  the  family  with  a  new  dish  occasionally. 

254.  Aesthetic  Considerations. — The  appearance  of  a 
dish  when  served  is  more  of  a  factor  in  its  proper  digestion 
than  is  always  realized.  A  dish  that  is  pleasing  to  the  eye 
whets  the  appetite  quite  as  much  as  one  that  is  pleasing  in 
flavor  and  lacking  in  attractiveness. 


FOOD  COMBINATIONS  IN  MEALS  147 

Salads  as  a  group  of  foods,  offering  as  they  do  essential 
foods  alone  or  in  combination,  furnish  endless  opportunity 
for  the  taste  and  originality  of  the  housekeeper  in  producing 
pleasing  effects.  The  plainest  and  most  ordinary  foods, 
by  a  tasteful  use  of  some  simple  garnish,  are  made  to  appear 
unusual  and  interesting.  Garnishes  should,  however,  be  of 
suitable  materials,  that  is,  should  be  some  kind  of  edible 
greens  or  other  food  substance.  Desserts  are  improved  in 
appearance  and  hence  in  digestibility  by  dainty  ways  of 
serving. 

255.  Protein  Foods. — The  protein  foods  are  sometimes 
classified  as  A,  B,  C,  and  D  proteins,  according  to  their 
value  in  the  nutrition  of  the  body.  To  the  A  proteins 
belong  the  animal  foods,  lean  meats  of  all  kinds,  fish,  eggs, 
and  milk,  because  they  contain  all  the  protein  units  which, 
when  taken  together,  form  the  body  proteins. 

Fish  are  plentiful  and  cheap  in  many  localities  and 
especially  so  in  sea  coast  towns  where  they  may  be  had 
fresh  from  the  water.  Fish  offers  a  satisfying  substitute 
for  the  red  meats  at  least  twice  a  week,  and  is  substantial 
enough  to  take  the  place  of  the  roast  in  the  ordinary  menu. 

Eggs  should  be  used  as  freely  as  the  income  will  allow, 
because  of  the  combination  of  protein  and  the  valuable 
vitamine  substances  (see  Chapter  XVI,  par.  226). 

Milk  should  be  provided  for  all  members  of  the  family 
but  more  especially  for  the  young  children.  An  allowance 
of  one  quart  of  milk  a  day  each  is  urged  for  those  members 
of  the  family  group  who  have  not  yet  reached  full  growth. 
This  amount  may  be  taken  on  cereals,  in  puddings,  etc., 
if  desired,  instead  of  as  a  beverage. 

It  has  been  said  that  as  much  money  should  be  spent 
for  milk  as  for  meat  in  every  household.  Even  at  the 
present  price  per  quart,  fifty  cents  will  purchase  more 
nutriment  in  the  form  of  milk  than  in  the  form  of  beef. 
Cheese,  a  product  of  milk,  is  a  highly  concentrated  form  of 
food  and  one  which  offers  a  good  substitute  for  meat. 


>• 


148  FOOD 

The  B  and  C  proteins  are  those  foods  which  are  rich  in 
protein  but  which  contain  more  of  other  foodstuffs.  In 
these  classes  not  yet  clearly  defined  we  have  the  cereals, 
nuts,  macaroni,  and  some  vegetables.  The  protein  content 
of  such  foods  is  inferior  to  that  of  animal  foods  because  the 
units  are  in  different  relation  to  one  another  than  the  pro- 
tein units  found  in  the  body.  In  vegetables  certain  of  these 
important  units  are  lacking  entirely.  However,  these  foods 
may  be  combined  with  left-over  meats  or  used  alone  occa- 
sionally to  furnish  a  sufficient  quantity  of  tissue  building 
material  for  the  day. 

To  the  D  proteins  belongs  gelatin,  which  is  of  food  value 
only,  as  a  ''protein  sparer,"  (see  par.  192)  since  it  in  no  way 
builds  or  repairs  body  tissue. 

256.  Carbohydrate  Foods. — Of  the  foods  classified  as 
carbohydrates,  starches  and  sugars  are  the  most  important. 
The  chief  sources  of  starch  are  the  cereals,  potatoes,  and 
bananas.  Since  it  is  necessary  for  normal  metabolism 
that  the  greater  number  of  calories  of  body  heat  be  produced 
by  carbohydrate  foods,  it  is  essential  that  some  kind  of 
cereal  food  form  a  part  of  the  daily  food  allowance.  The 
cereal  savers — potatoes,  sweet  and  white,  and  bananas — 
when  eaten  freely,  take  the  place  of  a  part  of  the  grain 
products  demanded. 

Sugar,  which  is  only  a  fuel  food,  should  be  taken  in 
combination  with  some  building  food,  such  as  milk,  eggs, 
etc.,  or  with  foods  containing  mineral  matter,  as  fruits  or 
green  vegetables.  Nearly  all  fruits  contain  sugar  and  may 
be  used  as  sugar  sparers,  since  less  sugar  is  required  when 
fruits  are  used  in  abundance. 

257.  Fats. — The  foods  classed  as  fatty  foods  are  butter 
and  butter  substitutes,  cream,  olive  oil,  bacon,  and  fat  from 
meat  and  nuts.  Butter  and  cream  are  probably  the  most 
important  sources  of  easily  digested  fat. 

258.  Mineral  Matter. — The  average  diet  provides  for 
the  ordinary  mineral  substances  of  the  body  in  sufficient 


FOOD  COMBINATIONS  IN  MEALS  149 

amounts.  But  the  importance  of  iron,  calcium  and  phos- 
phorus in  normal  nutrition  is  great  enough  to  warrant 
special  attention  in  selecting  foods  containing  these  in  larger 
quantities. 

Milk  is  the  chief  source  of  calcium  or  lime,  and  where 
it  is  used  plentifully,  a  proper  supply  of  calcium  is  provided. 
Iron  and  phosphorus  compounds  are  not  always  adequately 
supplied  by  a  freely  chosen  diet.  A  list  from  which  to 
select  foods  rich  in  the  above  minerals  has  been  supplied 
in  the  previous  chapter  and  attention  should  be  given  to 
selecting  an  abundance  of  these  foods  in  planning  meals. 

259.  Water. — Water  is  needed  to  supply  the  needs  of 
the  tissues  and  to  provide  the  fluids  of  the  body.  The  old 
predjudice  against  drinking  water  at  meals  has  been  super- 
seded by  the  belief  that  one  or  two  glasses  of  water  at  meals, 
if  not  taken  to  wash  dowTi  the  food,  are  beneficial.  The 
liquid  is  regarded  as  a  help  in  the  digestion  of  the  solid 
foods. 

260.  Desirable  Food  Combinations. — A  well  planned 
menu  leaves  no  room  for  criticism  in  regard  to  color,  flavor, 
and  attractiveness,  besides  representing  the  essential  food- 
stuffs. In  combining  foods,  the  flavor,  consistency,  and 
similarity  need  special  consideration.  Insipid  foods  require 
piquant  sauces.  Two  creamed  dishes  should  not  be  served 
at  the  same  meal,  nor  two  kinds  of  sauce  or  gravy  at  the 
same  time.  The  same  kind  of  food  should  never  be  served 
twice  in  the  same  meal;  for  example  tomato  soup  and 
stewed  tomatoes  as  a  vegetable,  or  fruit  as  an  appetizer 
and  as  a  salad  or  a  dessert.  Rich  desserts  are  not  needed 
after  a  hearty  dinner.  Fruit  ices  are  better  than  rich  creams. 
A  simple  green  salad  with  French  dressing  is  better  for  dinner 
than  the  heartier  cheese,  egg,  or  fish  salad  with  mayon- 
naise. A  hearty  chowder  or  vegetable  soup  calls  for  a  less 
heavy  meat.  Cream  of  vegetable  soups  are  more  suitable 
for  luncheon  and  may  furnish  the  hearty  part  of  the  meal, 
while  the  clear  soups,  consomme  and  bouillon,  are  better 


150  FOOD 

appetizers  at  the  beginning  of  a  hearty  dinner.  At  least 
one  succulent  vegetable  should  be  served  with  the  dinner. 

Certain  long-established  food  habits  determine  common 
food  combinations:  for  example,  apple  sauce  is  served  with 
pork  or  goose,  boiled  mutton  is  improved  by  caper  sauce, 
roast  lamb  by  mint  sauce  or  currant  jelly,  and  cheese  is 
relished  with  pie.  Back  of  each  of  these  natural  food 
choices  is  a  principle  which  is  recognized  as  the  body's 
effort  to  regulate  its  own  needs.  The  acid  of  apple  sauce 
in  the  first  instance  helps  to  digest  the  fat  in  pork  and  goose. 
The  sauces  bring  out  the  flavor  of  the  meat  in  the  second 
case,  and  the  cheese  furnishes  the  protein  which  the  pie 
'lacks.  These  examples  illustrate  the  normal  cravings  of 
the  body  for  foods  easy  of  digestion,  pleasant  of  flavor,  and 
balanced  in  foodstuffs. 

261.  Suggestions  for  the  Meals  of  the  Day. — (1)  Break- 
fast, which  is  the  simplest  and  most  informal  meal  of  the 
day,  may  consist  of  a  choice  of  the  following  foods: 

FruitSj  fresh  or  stewed.  The  mildly  acid  fruits  are  most 
desirable. 

A  cereal  served  with  cream  or  milk.  The  whole  grain 
cereals  are  preferred  because  they  furnish  all  of  the  nutrients 
of  the  grain. 

Meaty  consisting  of  chops  or  steak  or  meat  substitutes, 
eggs  served  in  many  ways,  small  fish,  bacon,  salt  fish. 

Bread,  hot  or  quick  breads  such  as  muffins,  popovers, 
Johnny  cake,  griddle  cakes,  waffles,  rolls,  or  toast, 

A  beverage,  as  coffee,  tea,  cocoa,  and  milk. 

(2)  Dinner,  which  is  the  heartiest  meal  of  the  day,  is 
served  at  night  or  at  the  noon  hour.  The  simple  dinner 
has  a  soup,  a  meat,  a  salad  and  a  dessert  course.  An  elab- 
oration of  these  foundation  courses  constitutes  the  formal 
dinner  menu. 

Soup — clear — consumme  or  bouillon. 

Meat — served  in  the  form  of  a  roast,  meat  pie,  steak, 
stew,  fish,  and  poultry. 


FOOD  COMBINATIONS  IN  MEALS  151 

Vegetables — potatoes,  and  one  other  vegetable. 

Salad — some  kind  of  green  salad  vegetable  with  Fjench 
dressing. 

Dessert — ices,  creams,  simple  puddings,  fruits,  with  tea 
or  coffee  and  milk. 

Soup  and  salad  are  not  necessary  at  the  same  meal  and 
one  or  the  other  may  be  eliminated  if  desired.  The  chief 
value  of  the  clear  soup  at  dinner  is  to  stimulate  the  flow  of 
the  gastric  juice  and  prepare  the  stomach  for  the  hearty 
meal  to  follow.  The  salad  course  offers  an  opportunity 
to  introduce  a  succulent  vegetable  into  the  menu,  the  value 
of  which  lies  in  its  mineral  and  water  content  and  the  addi- 
tion of  an  easily  digested  form  of  fat  in  the  salad  dressing. 

(3)  Limcheon  or  Supper,  as  the  case  may  be,  has  the 
same  number  of  courses  as  the  dinner,  but  is  made  up  of 
much  less  hearty  foods.  An  informal  luncheon  may  con- 
sist of  one  or  two  courses  only  and  still  offer  the  needed 
variety. 

Soup — cream  of  vegetable,  clam  chowder,  or  vegetable 
soup. 

Meat — a  hot  moat  dish  such  as  hash,  stew,  chops,  made 
dishes,  meat  substitute  dishes,  scalloped  dishes,  fish,  eggs. 

Bread  in  some  form. 

Vegetables — poatoes  such  as  creamed,  scalloped,  lyon- 
naise,  etc. ,  or  other  vegetables  prepared  in  a  simple  way. 

Salad. — The  salad  may  be  hearty  enough  for  the  main 
course  of  the  luncheon,  as  chicken,  fish,  egg,  cheese,  or  fruit 
with  mayonnaise  dressing. 

Dessert — fruits,  ices,  creams,  pastry,  cakes,  cookies, 

SUGGESTIONS  FOR  LABORATORY  PRACTICE 

In  connection  with  the  study  of  the  text  of  the  preceding  chapter: 
Plan  three  meals  a  day  for  the  different  seasons. 
Estimate  the  daily  food  requirement  and  plan  suitable  meals  to 
meet  this  requirement. 


152 


FOOD 


For  Winter: 


SAMPLE    MEALS 

Breakfast 

Stewed  Prunes 

Oatmeal  Cream  or  Milk 

Muflans  Omelet 

Coffee 


Breakfast. 

Amount. 

Calories. 

Stewed  prunes    .... 

4  or  5  medium 

100 

Rolled  oats 

2  tbsp.  (cooked) 

1  cupful 

100 

Thin  cream 

150 

Egg  muffins 

Butter 

2 

1  square  (1  tbsp) 

1  egg 

1  tbsp.  thick 

2  lumps 

131 
100 

Omelet 

Coffee: 

Cream 

Sugar 

116 

50 
50 

797 

Luncheon 

Mixed  Vegetable  Soup 
Spaghetti  and  Rice  Cheese  Sauce 

Gingerbread  Whipped  cream 

Tea 


Luncheon. 

Amount. 

Calories. 

1  cupful 

3  saltines 

75 

Wafers. 

50 

Spaghetti  and  rice  with  cheese  sauce .  . . 
Gingerbread  

f  cupful 

'  Piece  2  X2  in 

235 
115 

Whipped  cream 

2  tbsp.  (unwhipped). .  .  . 

2  thin  slices 

1  square  (1  tbsp.) 

100 

Bread. 

100 

Butter 

100 

775 

Dinner 

Barley  Soup 

Roast  Pork  Mashed  Potato 

Roasted  Onions  Apple  Sauce 

Roumaine  Salad  French  Dressing 

Tapioca  Sponge 

Coffee 


Dinjier. 

Barley  soup 

Roast  pork 

Ma.^ihed  potato  (seasoned) 

Roasted  onion 

Apple  sauce 

Roumaine  salad  and  French  dressing 

Tapioca  sponge 

Bread 

Butter 

Total  for  day 


Amount. 


1  cupful 

1  serving  (about  4  oz.). 

1  cupful 

1  large 

t  cupful 

1  small  serving 

f  cupful 

2  thin  slices 

1  square 


Calories, 


65 
320 
204 
.65 

96 
100 
241 
100 
100 


1291 
2843 


FOOD  COMBINATIONS  IN  MEALS 


153 


For  Summer: 

Breakfast 

Moulded  Farina  with  Fruit  Cream  or  Milk 

Toast  Coffee 


Breakfast. 

Amount. 

Calories. 

cupful  farina,  1  banana 

-  cupful 

2  slices    

175 

Whole  milk 

Toast 

63 
200 

Butter 

Coffee: 

Cream 

Sugar 

1  square 

1  tbsp  

100 
100 

638 

Luncheon  ' 

Cream  of  Spinach  Soup 

Fruit  and  Nut  Salad  Boiled  Dressing 

Graham  Tea  Biscuit 

Tea 


Luncheon. 

Amount. 

Calories. 

Cream  of  spinach  soup 

Wafers 

1  cupful 

3  Saltines 

178 
50 

Fruit  and  nut  salad  with  boiled  dressing . 

1  cupful 

234 
116 

Butter 

1  square 

100 

678 

Dinner 

Planked  White  Fish 

New  Potatoes  Butter  and  parsley 

String  Beans 

Cream  Cheese  and  Prune  Salad  French  Dressing 

Lemon  Ice  Cookies 

Coffee . 


Dinner. 

Amount. 

Calories. 

Planked  fish                                         .    . 

1  serving 

3  small,  1  tbsp.  butter .  . 
1  serving  (J  of  qt.) 

180 

Potatoes  with  butter  sauce 

String  beans 

Salad: 

200 
54 

75 

Cheese 

3  balls 

100 

1  serving 

3  saltines 

1  serving 

2  medium 

2  thin  slices 

1  square 

90 

Wafers 

Lemon  ice 

Cookies 

50 

120 

96 

Bread. .                                         ..... 

100 

Butter 

Total  for  the  day , 

100 

1165 

2481 

154 


FOOD 


For  a  Meatless  Day: 


Breakfast 
Orange 


Steamed  Barley 
Poached  Egg 


Cream  or  Milk 
Toast 


Coffee 


Breakfast. 

Orange 

Steamed  barley 

Thin  cream 

Poached  egg 

Toast 

Butter 

Coffee: 

Cream 

Sugar 


Amount 

1  large 

i  cupful 

i  cupful 

1 

2  slices 

1  square 

1  tbsp.  (thick). , 

2  lumps 


Calories. 


100 
60 

150 
67 

200 

100 

50 
50 


777 


Luncheon 
Baked  Beans 
Lettuce  and  Grapefruit  Salad 

Sponge  Cake 
Tea 


Brown  Bread 
French  Dressing 


Luncheon. 

Amount. 

Calories. 

i  cupful 

2  slices 

5  of  medium 

200 

Brown  bread 

150 

Salad: 

Grapefruit 

French  dressing 

1  serving. - 

140 

Sponge  cake 

Piece  2  X2  in 

169 

659 

Dinner 
Little  Neck  Clams 
Nut  and  Cheese  Loaf  Tomato  Sauce 

Stuffed  Baked  Potatoes  Lima  Beans 

Hearts  of  Lettuce  Russian  Dressing 

Deep  Apple  Pie 
Coffee 


Dinner. 


Little  Neck  clams  .  .  . 
Nut  and  cheese  loaf. . 

Tomato  sauce 

Stuffed  baked  potato. 

Lima  beans 

Lettuce  and  dressing. 

Bread 

Butter 

Deep  apple  pie 


Total  for  day 


Amount. 


^  doz 

1  serving. . . 
1  serving. . . 
1  medium. .  , 
J  cupful.  . . 

1  serving. . . 

2  thin  slices . 
1  square .  . . 
1  serving .  ,  . 


Calories. 


40 
389 

93 
116 
100 
224 
100 
100 
224 


1386 
2822 


FOOD  COMBINATIONS  IN  MEALS 


155 


For  a  Wheatless  Day: 


Breakfast 
Baked  Apple 
Fried  Corn  Mush 
Coffee 


Maple  Syrup 


Breakfast 

Baked  apple 

Fried  corn  mush 

Maple  syrup 

Coffee: 

Cream 

Sugar 


Amount. 

1  large 

1  serving 

2^  tablespoonfuls 

1  tablespoonfuls . 

2  lumps 


Calories. 


200 
100 
150 

50 
50 


550 


Luncheon 

Cream  of  Potato  Soup 

Lentil  and  Rice  Cakes 

Rye  Rolls 

Sliced  Pineapple  Oatmeal  Cookies 


Luncheon. 

Cream  of  potato  soup. .  . 
Lentil  and  rice  cakes. .  .  . 

Rye  rolls 

Butter 

Pineapple 

Oatmeal  cookies 


Amount. 

1  cupful 

2  (small) 

2  (medium) 

1  square  (1  tbsp.) 
1  slice 

3  (small) 


Calories. 


213 
205 
100 
100 
100 
75 


793 


Dinner 

Roast  Beef  Sweet  Potato  Pone 

Baked  Stuffed  Tomatoes 

Asparagus  and  Pimento  Salad  Mayonnaise  Dressing 

Cornmeal  Crisps  Butter 

Fruit  Whip 


Dinner. 

Amount. 

Calories. 

Roast  beef 

Sweet  potato  pone 

2  thin  slices  (size  of  hand) 
1  medium 

200 
250 

Baked  stuffed  tomato 

1  medium. 

35 

Salad 

1  portion 

60 

Mayonnaise  dressing 

Corn  meal  crisps  .                   

1  portion .  . 

224 

5  small 

50 

Butter 

1  square 

100 

Fruit  whip 

1  portion 

241 

Total  for  day 

1160 

2503 

CHAPTER  XXI 
THE  PRESERVATION   OF  FOODS 

262.  Why  Food  Spoils. — The  spoiHng  of  food  is  due  to 
two  agencies.  First,  the  action  of  bacteria,  yeast,  and  mold 
plants  causes  undesirable  and  sometimes  harmful  changes 
to  take  place  in  food  materials;  second,  there  are  present  in 
eggs,  meat,  and  the  seeds  of  plants  substances  having  the 
power  to  carry  on  certain  changes  in  the  foods.  These 
changes,  or  life  processes,  are  the  natural  ripening  and  matur- 
ing of  fruits,  the  growing  of  seeds,  and  the  final  decay  of  all 
substances. 

The  organisms  which  cause  the  fermentation  and  putre- 
faction of  food  materials  are  microscopic,  that  is,  they  can- 
not be  seen  without  the  aid  of  a  microscope.  Although  we 
are  unable  to  see  the  bacteria  and  other  micro-organisms, 
they  are  present  everywhere  in  the  air,  in  the  soil,  and  in 
water.  We  have  proof  of  their  activity  in  the  odor  of 
decayed  food,  the  gas  from  fruit  that  is  fermenting,  and  the 
mold  on  bread  and  other  foods.  These  micro-organisms 
exist  in  two  forms:  the  spore  stage  and  the  active  stage. 
When  conditions  are  not  right  for  their  growth,  they  enter 
the  spore  stage  for  rest.  In  this  form  they  are  able  to  resist 
for  hours  a  degree  of  heat  equal  to  the  boiling-point  of  water. 

All  micro-organisms  require  warmth,  moisture,  food, 
and  oxygen  for  normal  growth  and  development.  Con- 
ditions favorable  for  the  growth  of  bacteria  and  other  plant 
life  are  also  favorable  for  the  ripening,  maturing,  and  decay- 
ing processes.  Therefore,  if  the  food  is  to  be  kept  for  a 
period  of  time  it  is  necessary  to  protect  it  from  the  former, 
and  to  prevent  the  natural  changes  due  to  the  latter  by  some 
form  of  preservation. 

156 


THE  PRESERVATION  OF  FOODS  157 

263.  Ways  of  Preserving  Foods. — Foods  are  preserved, 
according  to  their  kind  and  condition,  by  any  one  of  the 
following  methods: 

(1)  By  the  use  of  low  temperature. 

(2)  By  the  use  of  high  temperature. 

(3)  By  the  use  of  preservatives. 

(4)  By  the  removal  of  moisture. 

264.  Low  Temperature. — By  keeping  them  in  cold 
storage  or  by  freezing,  many  foods  may  be  maintained  for 
months  in  a  fairly  good  condition.  The  low  temperatures 
interfere  with  the  growth  of  the  bacteria  which  causes 
putrefaction  and  decay.  Eggs,  meat,  butter,  fish,  and 
poultry  are  the  foods  most  commonly  kept  by  this  means. 

265.  High  Temperature  Canning. — Success  in  canning 
depends  upon  the  absolute  sterilization  (heating  to  the 
boiling-point  and  keeping  there  long  enough  to  kill  all 
living  organisms)  of  the  food  and  utensils  used  and  the  final 
exclusion  of  air  by  sealing  the  jar. 

A  common  method  of  canning  is  the  open  kettle  method 
in  which  the  fruit  or  vegetable  is  cooked  in  an  open  kettle 
and  then  packed  in  jars  and  sealed.  This  method  offers  too 
many  chances  for  troublesome  bacteria  to  enter  the  food  to 
be  entirely  satisfactory.  For  this  reason  the  open  kettle 
method  has  been  replaced  by  more  dependable  ones. 

The  One-period  Cold-pack  Method* — This  method  of 
canning  fruits,  vegetables,  meats,  and  fish  has  been  adopted 
for  use  in  the  home  canning-club  work  of  the  United  States 
Department  of  Agriculture  in  the  Northern  and  Western 
States.  By  cold-pack  is  meant  that  the  uncooked  cooled 
product  is  packed  in  hot  jars  and  covered  with  hot  liquid  of 

*  According  to  a  statement  given  out  by  the  Bureau  of  Chemistry  of  the 
United  States  Department  of  Agriculture  the  danger  of  the  food  poisoning 
known  as  "  Botulism  "  is  eliminated  by  boiling  the  contents  of  the  can  for  a 
few  minutes  before  eating.  The  Bacillus  Botulinus  and  the  poison  which 
it  produces  are  destroyed  by  this  treatment. 


158 


FOOD 


some  kind.  The  jar  is  then  partially  sealed  and  placed 
in  boiling  water  to  cook. 

By  one-period  is  meant  the  cooking  of  the  product  a 
sufficient  length  of  time  to  complete  the  process  at  one  time. 
This  method  necessitates  less  handling  of  the  jars  and  con- 
sumes less  time  than  the  method  known  as  intermittent 
sterilization. 

266.  Steps  in  Canning. — There  are  six  steps  to  be  ob- 
served in  the  cold-pack  method,  as  follows: 

(1)  Preparation  of  Food  Products  and  Utensils. — The 
jars  and   covers  should  be  washed,  placed  in  cold  water 


Fig.  37. — An  improvised  canning  outfit. 


and  heated  to  the  boiling-point.  The  foods  should  be 
washed  and  pared,  pits  or  cores  should  be  removed,  and  the 
foods  should  then  be  cut  in  pieces  when  too  large  to  use 
whole.  All  products  for  canning  must  be  clean,  sound, 
fresh,  and  not  overripe.  It  is  especially  important  that 
vegetables  for  canning  be  fresh  from  the  garden.  Most 
vegetables  lose  crispness  and  flavor  on  standing. 

(2)  Blanching  or  Scalding. — The  food  materials  should  be 
placed  in  a  colander,  frying  basket,  or  a  piece  of  cheese 
cloth,  and  lowered  into  boiling  water  or  live  steam  and  kept 
there  from  one  to  fifteen  minutes  according  to  the  kind  of 
product.  This  process  loosens  the  skin,  takes  out  any 
excess  of  acid,  and  preserves  the  coloring  matter  in  the  food. 


THE  PRESERVATION  OF  FOODS 


159 


(3)  Cold  Dip. — The  food  material  should  then  be  taken 
from  the  boiling  water  or  steam  and  plunged  at  once  into 
cold  water  (the  colder  the  better)  for  a  few  seconds  and 
then  drained. 

(4)  Packing. — The  cold-dipped  articles  should  be  packed 
at  once  into  the  hot  jars.  The  jar  should  be  filled  as  com- 
pletely as  possible.     If  a  vegetable,  one  teaspoonful  of  salt 


Fig. 


38.— Unsealed 
jar. 


Fig.  39. — Jar  ready  for 
sterilizing. 


Fig.  40. — Jar  com- 
pletely sealed. 


is  added  for  each  quart  of  material  and  the  jar  is  filled  with 
boiling  water.  In  the  case  of  fruit,  boiling  syrup  takes  the 
place  of  the  water  and  salt.  The  scalded  rubbers  and  tops 
of  jars  should  now  be  put  in  place  and  the  jar  partly  sealed. 

(5)  Processing  or  Sterilizing. — The  partially  sealed  jars 
should  be  lowered  into  a  water  bath  which  completely 
covers  the  jars  and  boiled  for  the  length  of  time  specified  in 
Table  XII,  for  the  particular  kind  of  food. 

(6)  Sealing. — When  the  jars  are  removed  from  the  hot 
water  bath  they  should  be  entirely  sealed  and  then  inverted 
to  cool.  When  sufficiently  cool  each  one  should  be  wrapped 
separately  in  paper  and  stored  in  a  cool  dry  place. 

267.  The  Intermittent  Method  of  Sterilization.— By 
this  method  the  food  is  sterilized  in  the  hot  water  bath  for 


160 


FOOD 


TABLE  XII.— TIME  FOR  CANNING  FRUITS  AND  VEGETABLES 
(Bulletin  U.  S.  Dept.  Agr.) 


Food  Material. 


Method  of  Preparation. 


Time  in  Minutes. 


Scalding  or 
Blanching. 


Sterilizing. 


Berries: 

Blackberries 

Blueberries . 

Gooseberries 

Raspberries 

Strawberries 
Soft  Fruits: 

Apricots  .  .  . 

Cherries. .  .  . 

Currants.  .  . 

Grapes 

Peaches .... 

Plums 

Hard  Fruits: 

Apples 

Pears 

Quinces .... 
Specials  egetables: 

Tomatoes .... 

Pumpkin 

Squash 

Sweet    Corn .  . 
Pod  Vegetables: 

Beans,  wax .  .  . 

Beans,  green. . 

Okra 

Cauliflower  .  . 
Root  Vegetables: 

Carrots 

Beets 

Turnips 

Greens: 

Chard 

Kale 

Asparagus.  .  .  . 

Spinach 

Beet  tops 

Dandelion .... 


Stem  or  hull,  rinse  in  cold  \ 
water,  pack  in  hot  j  ars  / 


Peel 

Stone 

Stem 

Seed 

Peel  and  stone . 
Wash 


Peel,  quarter  and  core , 
Peel,  cut  in  half,  core . 
Peel,  quarter 


Remove  skins 

Peel  and  cut  in  pieces. . 
Peel  and  cut  in  pieces. . 
Remove  husk  and  silk. 


Wash  and  string. .  .  . 
Wash  and  string. ... 

Wash 

Soak  in  brine  1  hour. 


Wash  and  scrape .  .  .  . 

Wash  and  scrape 

Peel  and  cut  in  pieces. 

Look  over  and  wash. . 
Look  over  and  wash  . 
Wash  and  scrape .  .  .  . 
Look  over  and  wash . 
Look  over  and  wash  . 
Look  over  and  wash. 


1-2 


1-2 


U 
U 
1^ 

n 

3 
3 
5 

5-10 

5-10 

5-10 

3 

5 
5 
5 


15  in 
15  in  1 
15  in 
15  in  1 
ISinl 
15  in  1 


live 


steam 
ive  steam 
ive  steam 
ive  steam 
ive  steam 
ive  steam 


16 


16 
16 
16 
16 
16 
16 

20 
20 
20 

22 
120 
120 
180 

120 

120 

120 

60 

90 
90 
90 

120 
120 
120 
120 
120 
120 


THE  PRESERVATION  OF  FOODS  161 

a  given  period  of  time  on  three  successive  days.  All  spores 
that  may  have  resisted  the  previous  boiling  processes  are 
destroyed  at  the  end  of  this  period.  This  extra  sterilizing 
is  not  always  necessary  but  is  considered  a  wise  precaution. 

268.  The  Use  of  Preservatives. — By  preservatives  is 
meant  such  substances  as  prevent  or  hinder  the  development 
of  micro-organisms  in  food.  They  may  be  classed  as  harm- 
less, of  doubtful  safety,  and  harmful.  The  harmless  preserva- 
tives are  sugar,  salt,  vinegar,  and  spice.  Those  about  which 
there  is  some  doubt  are  saltpeter  and  smoke.  The  use  of 
harmful  preservatives  comes  under  the  regulations  of  the 
Food  Laws  and  will  not  be  discussed  here. 

Sugar. — In  a  concentrated  solution  sugar  will  arrest  the 
growth  of  bacteria.  In  dilute  form  with  spices  or  vinegar 
it  is  also  a  valuable  aid  in  restricting  the  growth  of  organisms. 

Preserves  and  Conserves  are  mixtures  of  fruits,  nuts  and 
spices  with  a  high  percentage  of  sugar  to  make  them  rich 
and  to  control  the  growth  of  bacteria. 

Jams  and  Marmalades  are  also  rich,  sweet  compounds 
containing  the  juice  and  pulp  of  the  fruit.  They,  like  pre- 
serves, depend  upon  the  fifty  or  more  per  cent  of  sugar  to 
keep  them  from  spoiling. 

Jelly.* — The  jelly-making  substance,  pectin,  is  best 
obtained  by  cooking  the  fruit  with  water  until  the  juice  is 
freed  from  the  pulp.  Pectin,  a  substance  closely  related  to 
starch  in  chemical  composition,  is  an  essential  constituent 

*  The  United  States  Bureau  of  Chemistry  recommends  the  alcohol  test 
to  determine  the  amount  of  pectin  present  in  a  fruit  juice  and  incidentally 
the  amount  of  sugar  required  to  make  a  perfect  jelly.  Put  a  spoonful  of 
juice  in  a  beaker  and  add  to  it  a  spoonful  of  05  per  cent  grain  alcohol.  Shake 
gently  and  note  the  amount  of  pectin  precipitated.  If  the  precipitate  forms 
in  a  mass,  one  cupful  of  sugar  is  required  for  each  cupful  of  fruit  juice.  If 
the  precipitate  is  broken  up  into  several  parts,  one-half  to  three-fourths 
cupful  of  sugar  for  each  cupful  of  juice  is  needed  to  form  a  perfect  jelly. 
If  the  pectin  is  precipitated  but  not  in  a  mass,  the  proportion  of  sugar 
required  is  one-half  or  less  than  the  amount  of  juice  used.  Fruit  juice  that 
shows  *no  precipitate  in  this  test  is  lacking  in  pectin  and  will  not  make  jelly 
unless  combined  with  juices  rich  in  pectin. 


162  FOOD 

of  fruit  juice  that  is  to  be  used  for  jelly  making.  The 
amount  of  sugar  needed  for  a  perfect  jelly  must  be  in  pro- 
portion to  the  pectin  in  the  juice.  The  time  required  for 
cooking  depends  upon  the  degree  of  concentration  of  the 
juice. 

Salt  and  Vinegar  are  classed  as  preservatives  chiefly 
because  they  protect  food  materials  from  the  action  of 
micro-organisms  that  cause  decomposition. 

Spices. — Some  spices  are  slightly  effective  as  preservatives, 
others  are  entirely  lacking  in  power  to  prevent  the  decay  of 
food.  As  condiments  such  materials  stimulate  digestion 
and,  if  used  in  large  quantities,  are  harmful  because  of  the 
danger  of  over  stimulation  of  the  digestive  organs.  Highly 
spiced  foods  are  recommended  for  use  in  small  quantities 
as  condiments  rather  than  for  their  food  value. 

268.  Doubtful  Preservatives. — Saltpeter  is  used  in  curing 
meats.  It  prevents  the  removal  of  color  by  the  salt  in  the 
pickle.  Because  of  its  astringent  action  on  foods,  saltpeter 
is  of  doubtful  value  as  a  preservative. 

Smoke  owes  its  preservative  qualities  to  the  creosote  it 
produces.  It  is  sometimes  used  in  curing  beef,  tongue, 
hams,  and  dried  beef,  because  of  the  action  of  the  creosote 
in  arresting  the  growth  of  bacteria  and  also  for  the  flavor 
it  imparts  to  the  meat. 

269.  Removal  of  Moisture  or  Drying. — When  fruits  or 
vegetables  are  cut  in  thin  slices  and  spread  out,  they  begin 
to  lose  moisture  by  evaporation.  If  a  current  of  dry, 
warm  air  is  constantly  passed  over  them,  the  moisture  will 
evaporate  more  quickly  and  the  materials  will  soon  become 
dry  and  crisp. 

There  are  three  methods  by  which  the  moisture  of  fruits 
and  vegetables  may  be  removed.  The  sun's  rays  will 
evaporate  moisture  rapidly.  Many  fruits  and  vegetables 
are  successfully  dried  by  this  natural  agent.  Artificial 
heat  removes  moisture  quickly  and  the  heat  of  the  stove  has 
been  utilized  for  drying  purposes  in  the  many  patent  driers 


THE  PRESERVATION  OF  FOODS 


163 


now  on  the  market.  One  of  these  is  shown  in  Fig.  42. 
The  main  object  with  all  devices  is  to  reduce  the  food  sub- 
stances to  a  dry  leathery  mass  in  a  short  time.  In  applying 
artificial  heat  it  must  be  remembered  that  heat  greater  than 


Fig.  41. — Sun  drying. 
(U.  S.  Dept.  of  Agri  culture.) 


Fig,  42. — Drying  by  artificial  heat. 

150°  F.  is  liable  to  scorch  and  brown  the  food,  especially  at 
the  beginning  of  the  process. 

A  current  of  dry  air  constantly  passing  over  food  will 
dry  out  the  moisture  in  a  comparatively  short  time.  An 
electric  fan  makes  an  excellent  drier  at  small  cost. 

270.  Advantages  in  Drjdng  Fruits  and  Vegetables. — By 
adopting  some  method  of  drying,  the  surplus  of  perishable 


164  FOOD 

foods,  which  would  otherwise  be  wasted,  may  be  conserved. 
A  considerable  saving  in  the  cost  of  food  may  often  be 
effected  in  this  way.  Advantage  may  also  be  taken  of  an 
overstocked  market  and  fruits  and  vegetables  obtained  in 
quantity  at  relatively  low  prices.  When  properly  prepared, 
dried  fruits  and  vegetables  are  acceptable  substitutes  when 
fresh  varieties  are  out  of  season  or  scarce  and  high  priced. 

Drying  may  be  adopted  in  place  of  canning,  when  jars 
are  scarce.  The  dried  products  may  frequently  be  stored 
in  quantity  in  less  space  than  would  be  required  for  jars 
or  other  containers. 

271.  Preparation  of  Foods  for  Drying. — Vegetables  should 
be  scrubbed  clean,  peeled  or  scraped,  and  sliced  thin,  or 
put  through  one  of  the  various  patent  slicers  or  shredders, 

,to  make  the  pieces  of  uniform  thickness  so  that  they  will 
dry  evenly.  Blanching  is  desirable  for  vegetables  that  have 
a  strong  flavor  and  odor,  because  it  takes  out  some  of  the 
objectionable  flavor  and  odor  and  also  helps  to  soften  the 
fiber.  Fruits  are  prepared  as  for  canning  except  that 
larger  fruits  should  be  cut  in  small  pieces  to  facilitate  the 
drying  process. 

272.  Storing  Dried  Foods. — Food  materials  should  be 
packed  in  tightly  covered  containers  promptly  after  drying. 
Tin  cans  and  glass  jars  may  be  used,  but  pasteboard  recep- 
tacles with  tight  covers  or  even  paper  bags  are  protection 
enough  for  properly  dried  materials. 

To  test  when  foods  are  dry  enough  to  store,  place  a  crisp 
cracker  in  the  container  with  the  food  and  allow  it  to  remain 
overnight.  If  the  cracker  is  still  crisp  when  removed  in 
the  morning,  the  product  is  without  moisture. 

SUGGESTIONS  FOR  LABORATORY  PRACTICE 

In  connection  with  the  study  of  the  text  of  the  preceding  chapter: 
Can  fruits  and  vegetables  in  season  by  the  one-period,  cold-pack 
method. 

Dry  fruits  and  vegetables  in  season. 


GLOSSARY 

Absorption:     The  process  of  being  absorbed  or  swallowed  up. 

Accelerate  :     To  quicken,  or  hasten  a  process. 

Acid:     A  substance  capable  of  combining  with  a  base  to  form  a  salt, 

and  of  turning  blue  litmus  paper  red.     Sour  to  the  taste. 
Acidity:     Sourness  to  the  taste. 
Acidosis:     An  abnormal  body  condition  when  acid  is  present  in  the 

tissues. 
Acrid:     Sharp  or  bitter  to  the  taste;  causing  irritation. 
Adjunct:     Something  joined  to  another  thing  without  being  a  part 

of  it. 
Adulterate  :     To  make  a  substance  impure  by  mixing  with  it  another 

substance  of  less  value. 
Aerate  :     To  combine  with  gas. 
Alkali:     A  caustic  base  which  neutralizes  acids  and  turns  red  litmus 

paper  blue. 
Amino  Acids:     A  constituent  of  body  protein. 
Assimilation:     Conversion  of  food  into  the  substance  of  an  animal 

or  vegetable  body. 
Calorie:     The  unit  of  heat. 
Carbonate:     A   compound  formed  by  the  union   of   carbonic   acid 

with  a  base. 
Cell:     A  tiny  particle  of  matter  consisting  of  protoplasm,  in  which 

floats  a  nucleus,  surrounded  by  a  cell  wall. 
Cellulose:     The  plant  fiber  which  is  an  essential  part  of  the  wall 

membrane  of  plant  cells. 
Chlorophyl:     The  green  coloring  matter  of  plants. 
Coagulate:     To  change  from  a  fluid  into  a  curd  like  or  thickened 

mass. 
Colloid:     Semi-solid,  non-crystallizable  substance  hke  glue  or  jelly. 
Colloidal:     Containing  a  colloid  in  solution. 
Compound:     A  substance  composed  of  two  or  more  elements. 
Dialyzable:     Capable  of  diffusion  through  natural  membranes. 
Dietary:     A  fixed  allowance  of  food;  a  rule  of  diet. 
Dietetics:     The  science  of  diet;    the  study  of  food  and  nutrition  in 

health  and  disease. 
Diluent:     Making  thinner  or  weaker  by  admixture  usually  of  water. 

165 


166  GLOSSARY 

Disintegrate:    To  break  up.     To  separate  into  parts. 
Effervescence:    The  process   by  which   gas   is   given  off   from   a 

liquid. 
Effete:     Worn  out  with  age. 

Element:     The  simplest  form  of  matter  in  which  all  atoms  are  alike. 
Emulsion:     A  Hquid  full  of  tiny  fat  globules. 
Enzyme:     A  group  of  substances  found  in  plants  and  animals,  which 

has  the  power  of  decomposing  certain  carbon  compounds  found 

associated  with  them. 
Esophagus:     The  tube  which  takes  the  food  from  the  mouth  to  the 

stomach. 
Evaporate  :     To  pass  off  in  the  form  of  vapor. 
Ferment:     A  substance  formed  by  the  living  cell  and  capable  of  acting 

chemically  on  food  without  any  change  taking  place  in  itself. 
Fermentation:     A  chemical  change  of  organic  substances  by  which 

they  are  decomposed  and  recombined  into  new  compounds. 
Fibrin:     The  form  of  protein  found  in  coagulated  blood. 
Filter:     To  purify  by  passing  through  a  porous  substance. 
Filtrate:     The  substance  which  has  been  filtered  or  purified. 
Formula:     A  symbolic  expression  by  letters  or  figures,  of  the  chemical 

constituents  of  a  compound. 
Function  :     Appropriate  action  of  a  physical  organ. 
Inimical:     Opposed  to,  unfriendly. 
InuliN:     a  form  of  carbohydrate  found  in  many  plants;   heated  with 

water  or  dilute  acid  it  is  converted  into  laevulose. 
Intermittent:     Coming  and  going  at  intervals. 
Lacfeals:     That  part  of  the  lymphatic  system  which  carries  the  food 

from  the  intestines  to  the  thoracic  duct. 
Liver:     The  largest  gland  in  the  body,  lying  immediately  under  the 

diaphragm.     The  cells  of  the  liver  separate  certain  substances 

from  the  blood  and  manufacture  them  into  a  dark  green  liquid 

called  bile.     The  liver  cells  also  act  on  certain  parts  of  the  food 

brought  by  the  blood  vessels  from  the  intestines  and  hold  some 

of  it  in  storage. 
Lymphatics:     Small  blood  vessels  which  carry  food  from  the  intestines. 
Microbe:     A  small  living  thing. 

Micro-organism:     A  microscopic  organism,  as  a  bacillus. 
Mucous  Membrane:     The  lining  membrane  of  the  alimentary  canal. 
Nucleus:    A  differentiated  round  or  oval  body  embedded  in  the  proto- 
plasm of  a  cell. 
Nutrient:  -  Something  that  nourishes. 
Precipitate:     A  substance  which  separates  in  the  solid  state  when 

two  liquids  are  mixed. 


GLOSSARY  167 

Protoplasm:  An  albuminoid  substance  resembling  white  of  egg, 
and  capable  of  manifesting  vital  phenomena.  The  chief  part 
V  of  every  cell. 

Protoplasmic:     First  formed  as  a  constituent  of  organic  bodies. 

Ptomaine:     A  poison  developed  in  food  by  bacteria. 

Saturated  Solution:  A  solution  which  at  a  given  temperature  con- 
tains such  a  quantity  of  a  substance  that  the  two  are  in  equi- 
librium, there  being  no  tendency  for  more  of  the  substance  to 
pass  into  a  solution. 

Soluble  :     Capable  of  being  dissolved  in  a  fluid. 

Solution:  The  conversion  of  a  substance  from  the  solid  or  gaseous 
state  to  the  liquid  state  by  treatment  with  a  liquid. 

Solvent:  Any  fluid  or  substance  that  dissolves  or  renders  other  bodies 
liquid. 

Sterilize  :     To  render  free  from  living  germs. 

Pancreas:  A  gland  situated  in  the  abdomen  near  the  stomach  which 
pours  its  secretion  into  the  small  intestine. 

Parasite  :  An  animal  that  lives  on  or  in  and  at  the  expense  of  another 
animal.  A  plant  which  grows  upon  another  plant  or  upon 
an  animal  and  feeds  upon  its  juices. 

Peristalsis:  The  involuntary  muscular  movement  of  the  alimentary 
canal  whereby  its  contents  are  propelled  forward. 

Temperature  :     The  degree  of  heat  of  a  body. 

Tissues:    An  aggregation  of  cells  and  cell  products. 

Vacuum  :     An  empty  space. 

Volatile  Oils:  Substances  present  in  fruits,  flowers,  and  some  plants 
which  give  the  characteristic  odor  and  flavor. 


INDEX 


Acids,  amino,  2 

butyric,  83 

palmitic,  83 

oleic,  83 

stearic,  83 
Air,  as  a  leaven,  39 
Alimentary  canal,  diagram  of,  5 
parts,  5 
work  of,  5 
Amylopsin,  6 
Animal  food,  2 
Arrowroot,  22 
Artichokes,  71 

French,  74 

Jerusalem,  71 

Baking  powders,  analysis  of,  40,  41 

home  made,  42 

kinds,  40  ' 

Barley,  28 
Batter,  definition  of,  42 

drop-batter,  44 

pour-batter,  44 
Beans,  69 

appearance  of,  69 

composition,  69 

cooking,  69 

soy,  3 
Beef,  characteristics,  106 

cuts  of,  107,  108 
Beverages,  129 

effect  on  body,  134 
Bicarbonate  of  soda,  action  with 
acids,  41,  42 

source,  41 


Bile,  6 

Body  energy,  requirement,  140 

source,  1 
Breads,  44 

baking,  57 

digestibility,  61 

effect   of    ingredients    on   loaf, 
57 

judging  loaf,  61 

mixer,  57,  58 

mixing  and  kneading,  55 

quick  process,  55 

yeast,  54 
Brussels  sprouts,  74 
Buckwheat,  28 
Bulbs  as  foods,  72 
Butter,  83,  94 

composition  of,  95 

substitutes,  85,  95 

value  as  food,  85 

Cakes,  44 

baking,  50,  51 

butter,  46 

points  of  good,  51,  52 

sponge,  44 
Calcium,  126,  149 
Calorie,  141 

Canning,  157,  158,  159,  160 
Carbon  dioxide,  40,  41,  57,  60 
Carbohydrate,  2,  148 
Cellulose,  20 

cooking  of,  4 

digestion,  20 

food  value  of,  20 


169 


170 


INDEX 


Cereals,  24,  148 

as  breakfast  foods,  24 

common  cereals,  24 

cooking,  29 

digestion  of,  28 

sparers,  148 
Cheese,  kinds,  95 

value  as  food,  95 
Chloride,  sodium,  126,  136 
Chocolate,  composition,  133 

nutritive  value,  134 

source,  133 
Cocoa,  source,  133 

value,  133 
Coffee,  131 

adulteration,  132 

caffein,  130 

effect  on  body,  134 

experiments,  133 

preparation,  132 

substitutes,  132 
Compounds,  2 
Condiments,  value  of,  136 
Corn,  preparation,  26 

syrup,  26 
Crabs,  124 
Cream  of  Tartar,  40 

source  of,  41 

use,  42 

Dasheen,  71 
Dextrin,  12,  21 
Dextrose,  12 
Diet,  146 

variety  in,  146 
Digestion,  definition,  5 

process  of,  5,  6 
Dough,  44,  53 

soft,  44 

stiff,  44,  62 
Drying,  162 

methods,  163,  164 

storing,  164 


Eggs,  97,  147 

composition,  97 

digestibiUty,  98 

experiments,  103 

food  value,  98 

preparation  for  eating,  102 

preservation,  101 

selection  and  care,  99 

structure,  97 
Elements,  2 
Enzymes,  5 

Fat,  clarifying,  88 

composition,  2 

cooking  in,  87 

digestibility,  84 

experiments,  89 

function  in  body,  3,  84 

kinds,  85 

melting  point,  83 

milk  fat,  91 

properties,  83 

rendering,  88 

sources,  85 

test  for,  3 
Fehling's  solution,  3 
Fish,  118, 147 

choosing,  119 

common,  120 

composition,  118 

cooking  of,  1 19 

preserving,  120 

shell,  122 

special  kinds,  120 

unusual  kinds,  122 
Flour  mixtures,  39,  53 

classification,  42 
Fireless  cooker,  32 

home-made  cooker,  34 

principle  of,  33 

selection,  34 

use  of,  35 
Food,  absorption,  7 


INDEX 


171 


Food,  adults  and  children,  145 

amount  required,  140 

animal,  2 

assimilation,  7 

changes,  4 

classification,  1 

combinations,  149 

cost  of,  145 

definition  of,  1 

energy  value,  141 

need  for  growth,  140, 141 

preservation,  156 
Foodstuffs,  2 

composition  of,  2 

tests  for,  3 
Fructose,  13 
Fruits,  77 

canning,  158 

composition,  77 

dried,  79,  163 

food  value,  78 

preserving,  79 

selecting,  78 

storing,  79, 164 

Galactose,  13 
Gastric  juice,  6 
Game,  114 
Gelatin,  112,  148 
Gliadin,  54 
Glycerides,  83 
Glycerol,  83 
Glycogen,  14,  21 
Gluten,  54 
Glutenin,  54 
Guinea  fowl,  116 

Honey,  15,  16 
Hydrochloric  acid,  6 

Income,  143 
Inorganic  food,  1 
Intestine,  small,  6 


Intestine,  large,  7 
Iron,  126 

Jams,  80,  161 
Jellies,  80,  161,  162 

Lactose,  13 
Lamb,  110 
Leavens,  39 
Leavening  agents,  39 
Legumes,  67 

cooking,  69 

food  value,  68 
Levulose,  13 
Lipase,  6 
Lobster,  124 

Macaroni,  31 
Maltose,  5 
Maple  sugar,  15 
Marmalade,  80,  161 
Marrow,  86 
Meals,  143 

balanced,  146 

sample,  152,  153,  154, 155 

suggestions  for,  150 
Meat,  104 

composition  of,  104 

cooking,  105 

digestibility,  105 

experiments,  113 

food  value,  105 

kinds,  104 

ripening,  104 

selecting,  105 

structure,  104 
Milk,  care  of,  92 

certified,  93 

compositon  of,  90 

condensed,  93 

cooking  with,  94 

digestibility,  92 

food  value,  90 


172 


INDEX 


Milk,  malted,  94 

powders,  93 

modified,  94 

pasteurized,  93 

sterilized,  93 
Mineral  matter,  3,  148 

definition,  125 

function,  3,  125 

in  milk,  92 

sources,  126 

test  for,  3 
Molasses,  15 
Mussels,  124 
Mutton,  109 

Noodles,  31 

Nuts,  composition,  80 

digestibility,  80 

flavor,  80 

food  value,  81 

use  in  cooking,  81 

Oats,  preparation  and  food  value, 

24 
Oil,  86 

cod  liver,  86 

cottonseed,  87 

olive,  86 
Organic  foods,  1 
Organism,  1 

Organs,  internal  as  food,  111 
Oxidized  tissue,  1 

Pancreas,  7 
Pastry,  62 

baking,  62 

digestibility,  63 
Peptones,  6 
Pepsin,  6 
Phosphorous,  126 
Pork,  cuts  of,  101 
Poultry,  114 

composition,  114 


Poultry,  digestion  of,  114 

preparation,  116 

selection,  115 
Preservatives,  161 

kinds,  161, 162 

use  of,  161 
Pressure  cooker,  38 
Proteins,  2, 147, 148 

function  in  body,  3 

milk,  91 

test  for,  3 

wheat,  54 
Ptyalin,  5 

Rennen,  6 
Rice,  26 

Roots,  as  food,  71 
Rye,  28 

Sago,  22 

Salt,  126, 162 

Shrimps,  124 

Spaghetti,  31 

Spices,  137,162 

Squab,  116 

Starch,  as  body  regulator,  19 

composition,  18 

cooking,  20 

food  value,  18 

function  in  body,  19 

source,  18 

structure,  18 

tests  for,  3 
Steapsin,  6 
Sterilizing,  159 

milk,  93 
Sugar,  1,  148,  162 

body  regulator,  14 

cane,  13 

commercial,  15 

composition,  12 

digestion  of,  14 

disaccharides,  12 


INDEX 


173 


Sugar,  grape,  7 
monosaccharides,  12 
source  of  energy,  13 
sucrose,  13 
test  for,  3 

Tapioca,  21 
Tannin,  130 
Tea,  129 

classes,  130 

effect  on  body-;  134 

grades,  130 
Temperature,  10 

boiling-point,  10 
Terrapin,  124 

Thermos  bottle,  principle  of,  36,  37 
Tissue,  body,  1,  2 
Trypsin,  6 
Tubers,  71 
Turkey,  116 

Veal,  108 

Vegetables,  classification,  64 

composition,  64 

cooking,  65 

definition  of,  64 

digestion  of,  65 


Vegetables,  food  value,  65 

green  vegetables,  74 

selection,  65 
Vinegar,  136,  162 
Vitamines,  3,  127 

function  in  body,  128 

Water,  1, 149 

amount  required,  9 

as  body  regulator,  9 

as  cooking  medium,  10 

composition,  2,  8 

function  in  body,  8 

solvent,  8 

stimulant,  8 
Wheat,  as  breakfast  food,  24 

milling,  54 

structure  of  kernel,  53 

varieties,  53 

Yeast,  58 
conmiercial,  58 
compressed,  60 
dry,  60 

function  in  bread  making,  61 
liquid,  60 
sources,  58 


THE  WILEY  TECHNICAL  SERIES 

EDITED    BY 

JOSEPH   M.   JAMESON 


A  series  of  carefully  adapted  texts  for  use  in  technical, 
vocational  and  industrial  schools.  The  subjects  treated 
will  include  Applied  Science;  Household  and  Agricultural 
Chemistry;  Electricity;  Electrical  Power  and  Machinery; 
Applied  Mechanics;  Drafting  and  Design;  Steam;  Gas 
Engines;  Shop  Practice;  Applied  Mathematics;  Agriculture; 
Household  Science,  etc. 

The  following  texts  are  announced;  others  are  being 
added  rapidly: 

ELECTRICITY 

THE  ELEMENTS  OF  ELECTRICITY;  For  Technical  Students. 
By  W.  H.  TiMBiE,  Head  of  Department  of  Applied  Science, 
Went  worth  Institute.  xi4-556  pages,  5}4  by  8.  415  figures. 
Cloth,  $2.00  net. 

THE  ESSENTIALS  OF  ELECTRICITY;  A  Text-book  for  Wire- 
men  and  the  Electrical  Trades.  By  W.  H.  Timbie,  Wentworth 
Institute.  Flexible  covers,  pocket  size,  xiii+271  pages,  5  by  7^. 
224  figures.     Cloth,  $1.25  net. 

CONTINUOUS  AND  ALTERNATING  CURRENT  MACHIN- 
ERY. By  Professor  J.  H.  Morecroft,  Columbia  University. 
ix+466  pages,  5^  by  8.    288  figures.    Cloth,  $1.75  net. 

CONTINUOUS  AND  ALTERNATING  CURRENT  MACHIN- 
ERY PROBLEMS.  By  W.  T.  Ryan,  E.E.,  Assistant  Professor 
of  Electrical  Engineering,  the  University  of  Minnesota.  40  pages, 
SKbyS.    Cloth,  50  cents  ne/. 

5M-7-i.ig 


ALTERNATING  CURRENT  ELECTRICITY  AND  ITS  APPLI- 
CATION TO  INDUSTRY.  By  W.  H.  Timbie,  Head  of 
Department  of  Applied  Science,  Wentworth  Institute,  and  H.  H. 
Htqbie,  Professor  of  Electrical  Engineering,  University  of  Mich- 
igan. First  Course.  x+534pages*,  5^  by  8.  389  figures.  Cloth, 
$2.00  net. 

Second  Course,  ix+729  pages.  51  by  8.  357  figures.  Cloth 
$3.00  net. 

ELECTRIC  LIGHTING.     By  H.  H.  Higbie,  Professor  of  Electrical 

Engineering,  University  of  Michigan.     (In  preparation.) 
ESSENTIALS   OF    ALTERNATING    CURRENTS.      By  W.   H. 

Timbie  and  H.  H.  Higbie.     (In  Press,  Ready,  Fall,  1918.) 

HEAT  AND  HEAT  ENGINEERING 

HEAT;  A  Text-book  for  Technical  and  Industrial  Students.     By 

J.  A.  Randall,  Instructor  in  Mechanics  and  Heat,  Pratt  Institute. 

xiv+331  pages,  5M  by  8.     80  figures.     Cloth,  $1.50  net. 
GAS  POWER.     By  C.  F.  Hirshfeld,  Professor  of  Power  Engineering, 

Sibley  College,  Cornell  University,  and  T.  C.  Ulbricht,  formerly 

Instructor,  Department  of  Power  Engineering,  Cornell  University. 

viii  4-198  pages,  o}4  by  8.     60  figures.     Cloth,  $1.25  net. 
STEAM  POWER.     By  C .  F<  Hirshfeld,  Formerly  Professor  of  Power 

Engineering,   Sibley    College,    Cornell    University,    and     T.     C. 

Ulbricht,  formerly  Instructor,  Department  of  Power  Engineering. 

Cornell  University,      viii+419  pages,  5K  by  8.      228  Figures. 

Cloth,  $2.00  net. 
HEAT  AND  LIGHT  IN  THE  HOUSEHOLD.   By  W.  G.  Whitman, 

State  Normal  School,  Salem,  Mass.     {In  preparation.) 

MECHANICS  AND  MATHEMATICS 

ELEMENTARY  PRACTICAL  MECHANICS.  By  J.  M.  Jameson, 
Girard  College,  formerly  of  Pratt  Institute,  xii+321  pages,  5  by 
7M.     212  figures.     Cloth,  $1.50  ne^ 

MATHEMATICS    FOR    MACHINISTS.     By  R.   W.   Burnham, 

Instructor  in  Machine  Work,  Pratt  Institute  Evening  School. 
vii+229  pages,  5  by  7.     175  figures.     Cloth,  $1.25  net. 

PRACTICAL    SHOP     MECHANICS    AND    MATHEMATICS. 

By  James  F.  Johnson,  Superintendent  of  the  State  Trade  School, 
Bridgeport,  Conn,  viii+130  pages,  5  by  7.  81  figures.  Cloth, 
$1.00  net. 


PRINCIPLES  OF  MECHANISM.  By  Walter  H  .  James,  Assistant 
Professor  of  Mechanical  Engineering  Drawing,  Massachusetts 
Institute  of  Technology,  and  .Malcolm  C.Mackenzie,  Instructor 
in "  Mechanical  Engineering,  Massachusetts  Institute  of  Tech- 
nology. v+241  pages,  5}4  by  ,73^.    244  figures.   Cloth,  $1.50  net. 

ARITHMETIC    FOR    CARPENTERS    AND    BITILDERS.     By 

R.  BuRDETTE  Dale,  formerly  Director  in  charge  of  Vocational 
Courses  in  Engineering  and  Correspondence  Instruction,  Iowa  State 
College,    ix+231  pages,  5  by  7.     109  figures.     Cloth,  $1.25  net. 


SHOP   TEXTS 

MACHINE  SHOP  PRACTICE.  By  W.  J.  Kaup,  Special  Repre- 
sentative, Crucible  Steel  Company  of  America,  ix+227  pages, 
5M  by  8.     163  figures.     Cloth,  $1.25  net. 

PATTERN  MAKING.  By  Frederick  W.  Turner  and  Daniel 
G.  Town,  Mechanic  Arts  High  School,  Boston,  v+114  pages, 
5  by  7.    88  figures.     Cloth,  $1.00  net. 

PLAIN  AND  ORNAMENTAL  FORGING.  By  Ernst  Schwarz- 
kopf. Instructor  at  Stuyvesant  High  School,  New  York  City. 
x+267  pages,  Sj^  by  8.     Over  400  figures.     Cloth,  $1.50  net. 


DRAFTING  AND  DESIGN 

DECORATIVE  DESIGN.      A  Text-Book  of  Practical  Methods. 

By  Joseph  Cummings  Chase,  Instructor  in  Decorative  Design  at 
the  College  of  the  City  of  New  York  and  at  Cooper  Union  Woman's 
Art  School,  vi+73  pages.  8  by  10^.  340  figures.  Cloth, 
$1.50  net. 

AGRICULTURAL  DRAFTING."  By  Charles  B.  Howe,  M.E. 
viii+63  pages,  8  by  10^.    45  figures,  26  plates.     Cloth,  $1.25  net. 

ARCHITECTURAL  DRAFTING.  By  A.  B.  Greenberq,  Stuy- 
vesant Technical  High  School,  New  York,  and  Charles  B.  Howe, 
Bushwick  Evening  High  School,  Brooklyn.  viii+llO  pages, 
8  by  103^.     53  figures,  12  plates.    Cloth,  $1.50  net. 

MECHANICAL  DRAFTING.       By    Charles    B.    Howe,    M.E., 

Bushwick  Evening  High  School,  Brooklyn,  x+147  pages,  8  by 
lOM.    165  figures,  38  plates.    Cloth,  $1.75  net. 


ENGINEERING  DRAFTING.  By  Charles  B.  Howe,  M.E. 
Bushwick  Evening  High  School,  Brooklyn,  and  Samuel  J.  Berard, 
Sheffield  Scientific  School,  Yale  University.     (In  preparation.) 

DRAWING  FOR  BUILDERS.  By  R.  Burdette  Dale,  Director 
of  Vocational  Course,  Iowa  State  College,  v+166  pages,  8  by 
lOM-     69  figures,  50  plates.     Cloth,  $1.50  net. 


AGRICULTURE  AND  HORTICULTURE 

FIELD  AND  LABORATORY  STUDIES  OF  SOILS.  By  Pro- 
fessor A.  G.  McCall,  Ohio  State  University,  viii+77  pages, 
5  by  7.     32  figures.     Cloth,  60  cents  net. 

FIELD  AND  LABORATORY  STUDIES  OF  CROPS.  By  Pro- 
fessor A.  G.  McCall,  Ohio  State  University,     viii -1-133  pages, 

5  by  7.     54  figures.     Cloth,  85  cents  net. 

SOILS.  By  Professor  A.  G.  McCall,  Ohio  State  University.  (In 
preparation.) 

MARKET  GARDENING.     By  Professor  F.  L.  Yeaw,  Oasis  Farm 

6  Orchard  Company,  Roswell,  New  Mexico.  Formerly  Professor 
of  Market  Gardening,  Massachusetts  Agricultural  College.  vi  + 
120  pages,  5  by  7.     36  figures.    Cloth,  75  cents  net. 

THE  CHEMISTRY  OF  FARM  PRACTICE.     By   T.   E.    Keitt, 

Chemist  of  South  Carolina  Experiment  Station,  and  Professor  of 
of  Soils,  Clemson  Agricultural  College,  xii+253  pages,  5}4  by  8. 
81  figures.    Cloth,  $1.25  net. 

STUDIES  OF^TREES.  By  J.  J.  Levison,  Formerly  Forester,  Park 
Department,  Brooklyn,  N.  Y.  x+253  pages,  5H  by  8.  156 
half-tone  illustrations.     Cloth,  $1.60  ne^ 

AGRICULTURAL  DRAFTING.  By  Charles  B.  Howe,  M.E. 
46  pages,  8  by  10^.    45  figures,  22  plates.     Cloth,  $1.25  net. 

SCHOOL  ENTOMOLOGY.  For  Secondary  Schools  and  Agri- 
cultural Short  Courses.  By  E.  D wight  Sanderson,  Formerly 
Dean,  College  of  Agriculture,  West  Virginia  University,  and  L.  M. 
Peairs,  Professor  of  Entomology,  West  Virginia  University.  vii4- 
356  pages,  6  by  9.    233  figures.     Cloth,  $1.50  net. 


BIOLOGY 

lABORATORY    MANUAL   IN   GENERAL   MICROBIOLOGY. 

Prepared  by  the  Laboratory  of  Bacteriology,  Hygiene  and  Path- 
ology. Michigan  Agricultural  College.  xvi-[-418  pages,  51  by  8. 
73  figures.     Several  tables  and  charts.     Cloth,  $2.50  net. 

COSTUME  DESIGNING 

COSTUME  DESIGN  AND  ILLUSTRATION.  By  Ethel  H. 
Traphagen,  Instructor  and  Lecturer  at  Cooper  Union,  The  New 
York  Evening  School  of  Industrial  Art.  ix+145  pages,  8  by  10^. 
Upwards  of  200  figures,  including  several  in  colors  and  a  color 
spectrum  chart.    Cloth,  $2.50  net. 

PRINTING 

PRINTING.  A  Textbook  for  Printers'  Apprentices,  Continuation 
Classes  and  for  General  Use  in  Schools.  By  Frank  S.  Henry, 
Instructor  in  Printing,  Philadelphia  Trades  School,  ix+318  pages. 
153  figures.    5^  by  7^.    Cloth,  $1.25  net. 

DOMESTIC   SCIENCE 

FOOD:  ITS  COMPOSITION  AND  PREPARATION.  A  Text- 
book for  Classes  in  Household  Science.  By  Mary  D.  Dowd 
and  Jean  D.  Jameson,  Teachers  in  Household  Science,  Washington 
Irving  High  School,  New  York  City,  vii -1-173  pages,  5^  by  8. 
42  figures.    Cloth,  $1.25  net. 


THE   LOOSE   LEAF  LABORATORY  MANUAL 


A  series  of  carefully  selected  exercises  to  accompany  the  texts 
of  the  Series,  covering  every  subject  in  which  laboratory  or  field 
work  may  be  given.  Each  exercise  is  complete  in  itself,  and  is 
printed  separately.    8  by  10|. 


Important  Notice 
WILEY  LOOSELEAF  MANUALS 

The  sale  of  separate  sheets  of  the  Laboratory  Manuals  of  the  Wiley 
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literature  will  be  sent  on  request. 

CHEMISTRY 

Exercises  in  General  Chemistry.  By  Charles  M.  Allen, 
Head  of  Department  of  Chemistry,  Pratt  Institute.  An 
introductory  course  in  Apphed  Chemistry,  covering  a  year's 
laboratory  work  on  the  acid-forming  and  metallic  elements  and 
compounds.  62  pages,  8  by  103^.  61  exercises. 
Complete  in  paper  cover.    Removal  leaves.    $1.00  net. 

Quantitative  Chemical  Analysis.  By  Charles  M.  Allen,  Head 
of  Department  of  Chemistry,  Pratt  Institute.  12  pamphlets. 
8 by  103^.  Complete  in  paper  cover.    Removal  leaves.    %\.QOnet. 

Qualitative  Chemical  Analysis.  By  C.  E.  Bivins,  Instructor  in 
Quahtative  Analysis,  Pratt  Institute.  11  pamphlets,  supple- 
mented by  Work  Sheets  by  which  the  student  is  taught  equa- 
tions and  chemical  processes.  Complete  with  work  sheets  in 
paper  cover.    Removal  leaves.     $1.25  net. 

Technical  Chemical  Analysis.  By  R.  H.  H.  Aungst,  Instructor 
in  Technical  Chemistry,  Pratt  Institute.  19  pamphlets.  8  by 
103^.     Complete.    Removal  leaves.    $1.00  net. 

Exercises  in  Industrial  Chemistry.  By  Dr.  Allen  Roqees, 
Instructor  in  Quahtative  Analysis,  Pratt  Institute.  {In  prep- 
aration.) 


THE  LOOSE  LEAF  LABORATORY  MANUAL-Cont. 


MECHANICS  AND  HEAT 

Exercises  in  Mechanics.  By  J.  M.  Jameson,  Girard  College; 
Formerly  of  Pratt  Institute.  52  exercises.  Complete  in  paper 
cover.    Removal  Ifeaves.    85  cents  net. 

Exercises  for  the  Applied  Mechanics  Laboratory.  Steam; 
Strength  of  Materials;  Gas  Engines;  and  HydrauUcs.  By 
J.  P.  KoTTCAMP,  M.E.,  Instructor  in  Steam  and  Strength  of 
Materials,  Pratt  Institute.  8  by  103^.  58  exercises,  with 
numerous  cuts  and  tables.  Complete  in  paper  cover.  Removal 
leaves.    $1.00  net. 


ELECTRICITY 

Exercises  in  Heat  and  light.  By  J.  A.  Randall,  Instructor  in 
Mechanics  and  Heat,  Pratt  Institute.  17  exercises,  with  nu- 
merous cuts  and  diagrams.  8  by  10}/^.  Complete  in  paper 
cover.     Removal  leaves.    34  cents  net. 

Electrical  Measurements,  A.  C.  and  D.  C.  By  W.  H.  Timbie. 
Head  of  Department  of  Applied  Science,  Wentworth  Institute 
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Elementary  Electrical  Testing.    By  Professor  V.  Karapetoff, 

Cornell  University,   Ithaca,    N.   Y.    25  exercises.     Complete 
in  paper  cover.    Removal  leaves.    50  cents  net. 

Electrical  Measurements  in  Testing.  {Direct  and  Alternating 
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gineering, Harvard  University.  In  charge  of  Industrial  Elec- 
tricity, Frankhn  Union,  Boston.  39  Exercises.  Complete  in 
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THE  LOOSE  LEAF  LABORATORY  MANUAL-Con<. 


AGRICULTURE  AND  HORTICULTURE 

Studies  of  Trees:  Their  Diseases  and  Care.  By  J.  J.  Levison, 
M.F.,  Lecturer  on  Ornamental  and  Shade  Trees,  Yale  University 
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above  sold  separately.     50  cents  net. 

Exercises  in  Farm  Dairying.  By  Professor  C.  Larsen,  De- 
partment of  Dairy  Husbandry,  South  Dakota  State  College. 
Loose  leaf.  8  by  10|.  69  Exercises.  Complete.  Removal 
leaves.     $1.00  net. 


DRAWING 

AGRICULTURAL  DRAFTING  PROBLEMS.  By  Charles  B. 
Howe,  M.E.  A  Manual  for  Students  of  Agriculture  to  Sup- 
plement the  Text  in  Agricultural  Drafting,  26  plates.  8  by 
103^.     In  paper  cover.     Removal  leaves,     50  cents  net. 

THE  ORDERS  OF  ARCHITECTURE.  By  A.  Benton  Greenberq. 
A  Manual  for  Students  of  Architecture  to  Supplement  the 
Text  in  Architectural  Drafting.  20  plates.  8  by  10^.  In  paper 
cover.      Removal  leaves.     50  cents  net. 


"7 


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SEP   13    1936 


ma  22  1937 


NOV   1ft  1937 


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